Hitman's Pontiac Trans Am Forum
Trans Am Information => Aftermarket Questions => Topic started by: 19transam81 on March 16, 2012, 07:51:57 PM
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Hey guys, I have a 81 TA that was a auto car originally. Since then, the car has had a sbc 355 and a 4-speed muncie installed. Now, I really want the overdrive gears, so i want to go with a 5 speed or 6 speed so the car gets better mileage on the highway. My dad and I put the muncie in the car, and it wasn't too crazy of a job.
I need to know what parts I will need to convert the 4 speed setup to the 5 or 6 speed setup. I know there are kits available that come with everything you need, but I heard they are pricey. If someone has already done the swap, and can give me some insight on what I need and how difficult of a job it is, I would really appreciate it. Let me know if its a do-able conversion or if it is worth the extra money to buy a whole new kit and save some headaches. Thanks for your time!
-Cody
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get a deal on a T56 and youll love it... just finished mine... youll want an LT1 version, so 93-97... any newer and you might have some problems.... but is still workable... out of an Fbody will really help, youll need to get the hydraulic clutch stuff, or leave it mechanical and deal with it the same old fashioned way... but I reccomend the hydraulic stuff... its less pedal effort.. next youll need to either customize your crossmember, or buy one thats bolt in, I bought mine from www.gforce.com nice heavy duty unit... and your shifter will need to either be swapped for an adjustable unit, something a little different... mine is coming up through a custom hole, and I am using an automatic console... you DO NOT have to do the same way I did, mine was an auto car.... TAKID455 put one into a factory 4spd hole.... but he has a top of the line transmission.... your stock speedo wont work without an electronic conversion, like a cablex box or something similiar or an aftermarket tailhousing with the mechanical provision.... and depending on your rear gear ratio, you might have to change it, mine is a 3.04 and its too low, 3.73s min for a 6spd.... I barely get into 5th... 6th bogs down the engine... if you shop around and price it all right you can get a much better deal swapping in good used parts...
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So for my checklist of parts:
-T-56 tranny (93-97)
-Crossmember
-Custom shifter with an offset (I think hurst makes a part especially for this, although it is expensive. If you know a cheaper way to go let me know.)
-Converter to change the t-56 speedo from electonic to mechanical
What about a bellhousing? My block is a 78 350. Will the bellhousing off an older transmission bolt up to a T-56? I will prolly go with the mechanical clutch assembly, at least for now, so I will need a bellhousing to match up to my linkage? Or will the bellhousing off a 93-97 t-56 bolt up to my 78 block and work with the linkage I already have?
Also, what about driveshaft? I have the stock driveshaft so will I need to cut it? Or buy a completely different one?
Let me know what other parts I'm missing so I can get an idea of how much I'll be spending. Thanks for your time!
-Cody
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stock lt1 t56 will bolt right up.... same sbc bellhousing design...,
the lt1 version still has a shift fork, so the factory linkage will hook up just like it does on the factory 4spd...
driveshaft, I believe requires a new yoke, since you are going from 4spd to a 6spd... spline count and diameter are different... you can get yours cut and balanced for a good price...
shifter Ill get back to you, there is one that is fully adjustable in every which direction then you can set it in and lock it down with the set screws... lot of guys run this and I want to say the brand is White Lightning.... a tremec subdivision"?
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So this seems to be a relatively simple conversion then. I have found a couple rebuilt t-56's that come with the mechanical speedo conversion. Sounds like besides getting the driveshaft cut to length it should only be a days work. So, the crossmember you bought from gforce.com bolted right into the factory crossmember holes and lined up with the tranny with no fabrication? If thats the case, then besides the driveshaft being cut it should all basically bolt right up correct? Also, where did you pick up the correct yolk to fit the t-56? And ill be waiting to hear what you found out about the shifter! Thanks again for all your help! I really appreciate it!
-Cody
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By the way, I tried to price the aftermarket tailshaft with the mechanical speedo conversion in case i buy a t-56 that doesn't already have one installed. I can't find anything cheap. The one I did find was $1000, way out of my price range. Can you tell me where to find one reasonable? Thanks a million!
-Cody
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I believe Classic industries offers a complete 5 spd kit with 5th being an OD. Kinda pricey at around $3300 + shipping
but comes with driveline, shifter and all I believe. Also will fit in factory location where the 4spd was, console and all.
I thought about this one myself but no fundage.
Goodluck
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Also, JAM performance transmissions says that in order to use a 93-97 LT1 t-56 you will need an adapter plate to make the bellhousing bolt up to the block. (http://www.5speedtransmissions.com/t56_early_gm.html) Is this true? Sorry for all the questions, I'm just trying to figure everything out before hand so there will be no surprises. I have also read that the bellhousing will bolt up to the block, but you will need a special flywheel for the pre-86 blocks since they are 2 pc rear main seals instead of 1 pc.? Can anyone validate this? I'm also going to need a different starter I'm assuming? Thanks again for your time!
-Cody
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http://www.5speedtransmissions.com/t56_early_gm.html
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eroc022, that is the site where I got some of my info from. First it lists what parts you will need to bolt the T56 up to the pre 86 block with a hyd clutch kit. In that section it says nothing about an adapter plate and says the tranny will bolt right up. However, right after that, it says what parts you will need to make it work with the early mechanical clutch and it says you need an adapter plate as well as a different input shaft and bearing retainer. I don't understand?? Why would you need an adapter plate and input shaft for the mechanical setup and not for the hyd. setup? Is the information backwards? Just trying to make sense of it all, not that I'm doubting you, i just want to hear the same info from multiple sources before I try to tackle the job and end up not having everything I need. Thanks for all your time!!
-Cody
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Ok, I'm dumb. After re-reading that article numerous times it says you need the adapter plate and input shaft for mating a t-56 to a NON T-56 bellhousing. I missed that part. (I'm in grad school and have been studying all day for finals, my brain is fried haha)
So, as long as I get the 93-97 t-56 with its matching bell housing, it will bolt right up. Sorry for being dumb and asking so many questions when the answer was right in front of my face. Thanks again for all your help!
Now I am getting a little better understanding of what I am going to need. The list is as follows:
-93-97 T-56 (LT1 car) Would it be best to get one out of a Camaro or Firebird/Trans Am??
-GForce crossmember and transmission mount: $250
http://www.crossmembers.com/shop/product_info.php?cPath=18_21_26&products_id=91
-Centerforce Flywheel: $450
http://www.summitracing.com/parts/CTF-700107/
-Clutch Kit (Assorted Brands): $350-$450
http://www.summitracing.com
-Driveline Components Shifter: $250
http://www.americanpowertrain.com/Shifter-Mechanisms.html
-Mechanical Speedo Conversion: $300
http://www.jagsthatrun.com
-Shorten Driveshaft (unsure of price)
-T-56 driveshaft Yoke? (I know both the TH-350 and t-56 use 27 spline slip yokes, but I don't know if they are the same size. My car has the TH-350 slip yoke currently.)
-Starter?
If you can think of anything I'm missing or if anyone knows of a cheaper place to find these parts, let me know PLEASE!
Thanks for everything!!
-Cody
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http://www.nastyz28.com/forum/showthread.php?t=235823
look through all these....
xmember you can save money by cutting and flipping the mount on yours...
been looking for these for awhile! finally found em....all same install applies since you have a sbc... ls1 is different.... needs a spacer thats all....
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Well, thanks for roundin up all the info for me. I was unaware that you would need to cut the trans tunnel to fit the t56 in. As nice as it would be to have the 0.50 overdrive in 6th gear, I think it will be much easier to go with a TKO 600. I found American Powertrain and 5speedtransmissions offer a new TKO 600 and everything needed to install it in a 2nd gen trans am. The price is a little more than I wanted to spend, but it seems much less mods are needed and it will be a cleaner install. If anyone knows where I can find a cheaper combo on the TKO 600 let me know. The kits I mentioned earlier run about $2800 without the clutch kit, flywheel, bellhousing, or crossmember. Thanks again for all the help!
-Cody
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Just an FYI you really want a T56 from 94-97. In 93 there was an M28 and a M29. M28 has some strange gear ratios and is the weakest T56. The M29 is the better of the two with much better gear ratios. But it is still not as strong as the 94-97 boxes.
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you do not have to cut the transmission tunnel, the only thing I cut on mine, was a shifter hole, but mine was an auto, the one TAKID455 did didnt require to be cut either....
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If you are going thru the trouble of changing the tranny...dont put a 5spd in it, do a T-56. I was running over 400RWHP and spent plenty of time at the track and never broke the stock T-56. They are pretty strong. And the extra gear is VERY nice. I ran 4.10 gears and was a blast to drive and still did really good on the freeway. The 6spd is well worth the effort...
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and finding the lt1 version makes it cheaper!
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food for though...
while 0.50 OD sounds nice, you need the torque at that RPM to use it or the engine bogs. Think of the 10th gear on the bike going up a slightly incline, unless you have strength or prior speed, it will be tough.
for the cost conscientious, install a Richmond/ Doug Nash 5 spd , swap in 2.73 rears and call it a day. Still 1:1 5th but has a deep 1st to move from a stop. Could probably use 2.56 gears if you wanted. Can find all you need 2nd hand for under 1500. If I didn't mention a part, it is not needed for the swap. I run this in a 74 T/A back by a stout 455 w/o issues after 10k miles. I get 16-18mpg on highway cruising 2500-3000 rpm. speed is .03*RPM
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food for though...
while 0.50 OD sounds nice, you need the torque at that RPM to use it or the engine bogs. Think of the 10th gear on the bike going up a slightly incline, unless you have strength or prior speed, it will be tough.
for the cost conscientious, install a Richmond/ Doug Nash 5 spd , swap in 2.73 rears and call it a day. Still 1:1 5th but has a deep 1st to move from a stop. Could probably use 2.56 gears if you wanted. Can find all you need 2nd hand for under 1500. If I didn't mention a part, it is not needed for the swap. I run this in a 74 T/A back by a stout 455 w/o issues after 10k miles. I get 16-18mpg on highway cruising 2500-3000 rpm. speed is .03*RPM
couldnt you also regear the rear end to change your overall od ratio ? I know my 3.08s now hate 6th gear... it bogs it down.... unless im doing 100, then its cruises and keeps going.... I know my motor has torque and power, Its set up like a 4th gen..... but 4th gens had 3.73 rear gears with the 6spd.... and most guys go to 4.11s
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Essentially, that is what the 5spd does. your 1-4 gears are 'normal' and then the 5th 'acts' as an overdrive. You can choose from 3 diff 1st gear ratios (3.27,4.06 or 4.56(?)) The kicker is 2-5 dont change so you have an increasing gear split the lower you go. OK for all around, no so good for say drag racing or jack rabbit starts.
The OP can do that w/ the 4spd but 1st is going to be very long and sluggish with a 2.43 ratio(ST-10) 1st or 2.20 for the muncie.
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food for though...
while 0.50 OD sounds nice, you need the torque at that RPM to use it or the engine bogs. Think of the 10th gear on the bike going up a slightly incline, unless you have strength or prior speed, it will be tough.
for the cost conscientious, install a Richmond/ Doug Nash 5 spd , swap in 2.73 rears and call it a day. Still 1:1 5th but has a deep 1st to move from a stop. Could probably use 2.56 gears if you wanted. Can find all you need 2nd hand for under 1500. If I didn't mention a part, it is not needed for the swap. I run this in a 74 T/A back by a stout 455 w/o issues after 10k miles. I get 16-18mpg on highway cruising 2500-3000 rpm. speed is .03*RPM
couldnt you also regear the rear end to change your overall od ratio ? I know my 3.08s now hate 6th gear... it bogs it down.... unless im doing 100, then its cruises and keeps going.... I know my motor has torque and power, Its set up like a 4th gen..... but 4th gens had 3.73 rear gears with the 6spd.... and most guys go to 4.11s
Actually...4th gen A4's came with 3.23's and 6spds came with 3.42...I upraded mine to 3.73, then later again to 4.10. Yes, 6th gear will bog with 3.42's, but it is a OD gear...its not meant to climb hills or gain speed. Think about a 4spd auto...when its in OD, it doesnt take much pedal to make it kick out of OD...I still say an LT1 T-56 is the way to go...
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food for though...
while 0.50 OD sounds nice, you need the torque at that RPM to use it or the engine bogs. Think of the 10th gear on the bike going up a slightly incline, unless you have strength or prior speed, it will be tough.
for the cost conscientious, install a Richmond/ Doug Nash 5 spd , swap in 2.73 rears and call it a day. Still 1:1 5th but has a deep 1st to move from a stop. Could probably use 2.56 gears if you wanted. Can find all you need 2nd hand for under 1500. If I didn't mention a part, it is not needed for the swap. I run this in a 74 T/A back by a stout 455 w/o issues after 10k miles. I get 16-18mpg on highway cruising 2500-3000 rpm. speed is .03*RPM
couldnt you also regear the rear end to change your overall od ratio ? I know my 3.08s now hate 6th gear... it bogs it down.... unless im doing 100, then its cruises and keeps going.... I know my motor has torque and power, Its set up like a 4th gen..... but 4th gens had 3.73 rear gears with the 6spd.... and most guys go to 4.11s
Actually...4th gen A4's came with 3.23's and 6spds came with 3.42...I upraded mine to 3.73, then later again to 4.10. Yes, 6th gear will bog with 3.42's, but it is a OD gear...its not meant to climb hills or gain speed. Think about a 4spd auto...when its in OD, it doesnt take much pedal to make it kick out of OD...I still say an LT1 T-56 is the way to go...
my bad mis type... you sir are correct!
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Correct me if I am wrong but isn't it true he could get an LS1 version and get the adapter plate and use his current bell housing and clutch setup? It would simplify things and he could keep his mechanical clutch linkage.
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In short yes. However, internally the LS1 units are better. Dont recall off hand what exactly. For some reason, I crossed them off the 'acceptable' list.
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Yeah the rumor is the LS1 version are weaker as they are made in Mexico where the LT1 versions are US made, but it is just a rumor. And even so the power levels needed to break one is still pretty high.
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Just food for thought here...the T56 is also used in the Dodge Viper and Chrysler Hemi Challenger's. The only difference's is input shaft, gear ratios and bellhousing. Just saying... and, seriously TX is correct. It's an OD gear...you're not supposed to be able to "pass" anyone in it. You down shift into 5th. I have a '93 Z28 with an LT1 and I love it. I can drive at 100MPH and the RPMs stay around 2,200. I love it when traveling. I am on vacation this whole week and I had to drive 200 miles to my destination and I only used a little over a 1/4 tank getting here cruising at 85-100 MPH at any given time. Who needs a 4-cyl. when you have the 6-spd?
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My thoughts exactly. I plan on trying to score an LS1 T56 for my 79 someday.
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cruising at 85-100 MPH at any given time. Who needs a 4-cyl. when you have the 6-spd?
I guess they don't believe in speed limits in FL
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cruising at 85-100 MPH at any given time. Who needs a 4-cyl. when you have the 6-spd?
I guess they don't believe in speed limits in FL
No, they do. Just they're kinda under staffed to catch us all especially whe we're on the Turnpike where everyone is doing the same speed just about. Haha. =P
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Sucks here in bc as right after the olympics they made all the laws harsher . Exceeding the speed limit by 25 mph and your car is automatically impounded ,huge fine and points .
I was going to do a stroker and maybe a T56 but there's really no point when you live in a communist part of the country .
And read this quote from our dictator
" Additionally, the Motor Vehicle Act now makes careless acts such as wheelies and doughnuts subject to a seven-day impoundment, de Jong said."
Sure glad I got rid of my dirt bike
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Sucks here in bc as right after the olympics they made all the laws harsher . Exceeding the speed limit by 25 mph and your car is automatically impounded ,huge fine and points .
I was going to do a stroker and maybe a T56 but there's really no point when you live in a communist part of the country .
And read this quote from our dictator
" Additionally, the Motor Vehicle Act now makes careless acts such as wheelies and doughnuts subject to a seven-day impoundment, de Jong said."
Sure glad I got rid of my dirt bike
As it should be.
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I see you guys are reffering to the T56 that has the 0.5 overdrive . Why not get the other version with a .8 fifth and a .62 sixth . Makes more sense to me .
So in theory if you we're running a 4.10 rear ratio the 0.5 OD would sort of work but then your first gear would seem awfully short and nothing more than wheel spin .also your driveshaft would be spinning faster than I would be comfortable with .
Am missing something here?
If I do this its going to be a 3.42 rear ratio with the .62 OD
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The .62 T56 out of the Fbody is a 93 only trans and is the weakest of them all. Plus there are two different gear ratios for that year. There is the M28 with 3.36 1st and the better M29 with 2.97 1st. Both have .62 6th gear. I have the M29 in my 85 and it is a great trans but overall the torque rating on the M28 and M29 is lower than the later versions. I run this trans with a 3.27 rear gear and I cruise at 65 MPH at around 1800 RPM in 6th gear.
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But isn't the t56 from keisler newly designed , or does it still have those flaws ?
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If you want to buy a brand new trans that is fine. But a lot of people like myself would rather find an OEM unit and rebuild it and save a few bucks. In my case I got the trans for $400 that was locked up. It needed a main shaft and a first gear. I got that along with a full rebuild kit and I now have a fresh trans for under $1000. I highly doubt you will find a new T56 for anything close to that.
Then there are those where money is no object and can buy a brand new T56 Magnum. I unfortunately am not one of those people.
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So for my checklist of parts:
-T-56 tranny (93-97)
-Crossmember
-Custom shifter with an offset (I think hurst makes a part especially for this, although it is expensive. If you know a cheaper way to go let me know.)
-Converter to change the t-56 speedo from electonic to mechanical
What about a bellhousing? My block is a 78 350. Will the bellhousing off an older transmission bolt up to a T-56? I will prolly go with the mechanical clutch assembly, at least for now, so I will need a bellhousing to match up to my linkage? Or will the bellhousing off a 93-97 t-56 bolt up to my 78 block and work with the linkage I already have?
Also, what about driveshaft? I have the stock driveshaft so will I need to cut it? Or buy a completely different one?
Let me know what other parts I'm missing so I can get an idea of how much I'll be spending. Thanks for your time!
-Cody
I put a TKO 5-speed in mine. Bought the whole kit from Restore a muscle car. American Powertrain made the kit. I stayed with the mechanical linkage. I had to open up the hole in the floor board since the trans sits dead center in the tunnel where as the OE 4-speed did not. Also installed 3:73's in the rear too. It would appear that the factory shifter may not work, snce it would sit up way to high.So I may go with an aftermarket short throw.