Author Topic: Which Edelbrock parts to use for 78 TA / L78 / YA and a TH400 tranni  (Read 1904 times)

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Offline RedDevilTA

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Hey there,

I am a noob and want to get good performance out of my engine, torque is very important to me....  ;D

I looked on the Edelbrock page and some forums for information but i am still not sure what to buy.

It would be grate to hear some suggestions..... i want to change camshaft, Heads, Intake and Carb.

Engine: L78      Code: YA       Tranni: TH400


Greetings from Liechtenstein
Phillip

Offline anuglyguy

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Re: Which Edelbrock parts to use for 78 TA / L78 / YA and a TH400 tranni
« Reply #1 on: January 17, 2015, 08:59:58 PM »
Get on to butler performance they will hook you up with everything you need.

Offline 72blackbird

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Re: Which Edelbrock parts to use for 78 TA / L78 / YA and a TH400 tranni
« Reply #2 on: January 22, 2015, 08:41:15 PM »
An L78 400 uses a no. 500557 400 block- it's too weak to handle a 4.21" or a 4.25" stroker kit. The main cap saddles on a 500557 are too thin, and typically crack at the dowels that locate the main caps. Look for a 71-75 no. 481988 400- these are much stronger and thicker in the main saddle area, and can handle 650-700 hp, even with 2-bolt caps. A 455 is also a good alternative foundation for a high performance build- 71-74 no 485428 blocks are good to use, as well as earlier 70 blocks.

Once you have a 489188 block, you can add a 4.21", 4.25", or even 4.5" stroker kit. A 455 can also be used- if you don't plan to go over 500-550 hp, the stock nodular crank is more than adequate. Butler Performance is also not the only source for Pontiac internals. KRE, SD Performance, Sandoval Performance, CVMS, Pontiac Dude, DCI Motorsports are all well known high performance Pontiac builders. All sell rotating kits, ported heads, cams, too, so check with them before you buy anything. Keep in mind these builders aren't cheap either, so prepare to spend some money if you want big hp.

Geno

Offline jonathonar89

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Re: Which Edelbrock parts to use for 78 TA / L78 / YA and a TH400 tranni
« Reply #3 on: January 23, 2015, 01:10:36 PM »
For starters, the Edelbrock performer rpm intake manifold and WFO drop base air cleaner would simplify your engine setup.  You can get that intake in good used condition for $100-$150 and the WFO from Butler Performance. 

New carb is not necessary for performance...quadrajets are 800cfm and can be tuned to meet your specific needs. 

A popular carb tuning tool these days is the innovate wideband kit.  You can get your carb and current setup dialed in very well for some nice all around gains.

There's too many options really.  You can simply get your stock heads and intake ported out, add a cam and make 400-500+hp or pay the expense of aftermarket parts to make some more power.  Can even throw a supercharger or turbocharger on your stock engine and make crazy power.

Offline RedDevilTA

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Re: Which Edelbrock parts to use for 78 TA / L78 / YA and a TH400 tranni
« Reply #4 on: January 28, 2015, 12:09:14 PM »
Hey, thanks.   :D

Can i use my current engine if I dont go over 450-500HP?

Phil

Offline 72blackbird

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Re: Which Edelbrock parts to use for 78 TA / L78 / YA and a TH400 tranni
« Reply #5 on: January 30, 2015, 07:24:35 PM »
Phil,
I've pulled apart more than one 500557 400 that had cracked main cap saddles- these engines were mild builds, less than 400 hp. I used to say it was okay to use these blocks for 350-400 hp builds, but after seeing how weak these blocks are, I'd only use them for stock builds now. Do yourself a favor and find a 481988 400 block.

Geno

Offline jonathonar89

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Re: Which Edelbrock parts to use for 78 TA / L78 / YA and a TH400 tranni
« Reply #6 on: February 01, 2015, 02:28:38 AM »
Hey, thanks.   :D

Can i use my current engine if I dont go over 450-500HP?

Phil

Your safest modifications would be to have your stock intake and cylinder heads ported then put a nice exhaust on it.  Can make nice power on that setup without going over your head on everything.  Parts can transfer over if you have problems with the block.