Topic: 3.73 rear end

[1981turbotransam]

does anyone know what would happen if i changed the 3.08 rearend from my 80 301t pace car to a 3.73 what kind of improvemnt would i get of what would happen

[rad400]

You will get some get up and go,but if you drive it around or on the interstate that you will tach 4 grand at 80mph about 3 grand for 60 mph fuel will go down from full to E. alot quicker. I have a 406 with 3:73 can't really drive to much above 55 on the street. It is nice at the track.

[gotsmoke?]

I have the 400 4spd with 3:73.  He is right, the RPMs are a bit much on todays freeways.  All I do is smoke 1st and 2nd gear if I launch too hard.  The other side is you ruin the clutch if you try to launch hard and not spin (tires).  Of course technique is everything, but I don't drive it hard all the time.  I will change back to 3:23 or maybe 3:08 before the summer.  I get 9 MPG!  I don't even know why I figured it up, but I did. 

[brian c]

With a pretty decently built 455, 3 spd auto, and 3.42:1 out back I'm getting 13mpg IF I keep it under 60. Anything above that and forget it. I was talked out of 3.73:1 gears when I had my rear axle rebuilt. Only way I'd do 3.73:1 is with an OD tranny and that might be pushing it as well.

[1977TASE]

Does the shifter for the six speed make you modify the center console?

[1977TASE]

Thanks Hammer. Any contact info for gear vendors?

[LOMILETA]

It is not a 6 spd in the normal sense, it actually takes your stock 350 trans and cuts all of the 3 gears in halves. You unblot the tail shaft housing, and bolt the GV unit on. Then you wire it up and your all set. The only problem we faced when installing it was we had to cut the seat brace out of the floor under the trans hump. For that reason an actual 700r4 or a 2004r is the way to go.

[1977TASE]

Using those transmissions, will I need to modify my center console? I want the drivability but to look as original as possible.

[LOMILETA]

not at all. I have a 2004r in my TA and the only mod was to move the trans crossmember 2 inches back. Even the stock drive shaft worked. There is also a company called shift works, that makes a OD swap kit for the shifter. It takes 10 mins to install and its under the console, and lastly they make a sticker that goes where the gear  selector is, and has letters that look factory

[1977TASE]

Thanks a bunch, this is great info. The car is about finished after 3 years of restoration. I will probably try and do it this summer, this will give us a few months to enjoy it before tearing it down again.
About savng the transmission, I have purchased enough parts to build another TA if I had another shell. I get on ebay and can't control myself.

[1977TASE]

Does the 4 spped automatic offer enough? Can it handle the torque?

[LOMILETA]

Well, my motor makes 575 hp and 565 lb/ft of torque. The guy that built mine builds them for Grand Nationals that run in the 9 second range. I spent $ 1250 on mine without a core. Try to find a shop trans that specializes in 2004r and 700r4's.
 

[1977TASE]

I can't express how great this is to get knowledgeable information. Does the 4 speed drop the rpm much at highway speeds? my T/A has 3.23's and 405hp.

[LOMILETA]

my car also has the 3:23's, and runs about 2300 at 70mph

[Keith]

What made you choose the 200r4 over the 700r4?
I've read that the 700r4 is a little stronger and has a lower 1st and 2nd gear.
Is the 200r4 an easier swap?
Also, what gears are you running in the rear end? RPM at 60, 70??
Sorry for all the questions, but I would like to install a 4spd auto in a year or so.
Thanks for the info,

Well, my motor makes 575 hp and 565 lb/ft of torque. The guy that built mine builds them for Grand Nationals that run in the 9 second range. I spent $ 1250 on mine without a core. Try to find a shop trans that specializes in 2004r and 700r4's.