It needs to be able to handle up to 500HP and it can absolutely not have any computer involved. I plan on running either 3.08, 3.23 or 3.43 gears in the rear end. Anybody have an idea on what tranny I should look at getting and why?

 

Well for starters are you looking for a stick or auto ?

 

Preferably an automatic.

 

If you want to stay away from computer controlled and support 500hp I would use turbo 400 but they do make a non computer controlled 700r4 but you will have to put some work into a 700r4 to Handel 500hp. Check this thread https://www.thirdgen.org/forums/tran...led-700r4.html

 

Th400. I've got mine and its holding up good so far

 

I was thinking TH400, but the extra gear with a 700R4 would be nice to have, what year did they start making the 700R4 computer controlled?

 

I believe 84 was the last year for a non electronic 700r4 but I've bin told it is very easy to wire up a newer one and its all self contained in the trans just a positive wire going in. My 90 firebird has the 700r4 and when I went carbureted I took the computer out for my girls 92 the car still shifts the same and it's bin that way for 5 months now.

 

Technically any 700R-4 is non-computer, if you rig up a 1-wire lockup or buy a non-lock converter and an aux cooler. Early 700R-4s can be rigged for hyd lockup, but nobody builds those to hold 500 HP. The only year with all the upgrades and the ability to hyd lockup is '87. The TH400 is the second choice, but I'd want an aftermarket 2.75 / 1.57 / 1.00 gear set in it.

 

Thanks for the help 86Iroc/Z28, I think that is what I will go with than.

 

If 500hp is the max you would ever have, then get a th350.

Their cheap, and lighter than a th400.
And almost a direct bolt it (as long as you use the long shaft th350.

I have a built th350 and I am low 11's with a 3650lb(with me in the car).

 

The '88 700R4 still had the lockup valve bore but has a dummy plug installed. If you can find this valve body you can order the valve from Transgo to replace the dummy valve. If the lock up bore is not present you could also have a machinist and drill it out. Either way, I would use an 87+ core with the SECOND design valve body.

 

Alright thanks guys.

 

They're cheaper and lighter than the TH400 because they don't have any center support in there, compared to the TH400. This is why ALL of my TH350s failed me sooner or later. One was just cruising down the interstate! 700R-4 failures have many , many, many different causes, but at least they have the low first that never fails, the lockup, and the overdrive, to make the hassle worthwhile.

 

My 700r4 was good, until I started hitting low 11's. Then the 700r4 would just not last.

The 700r4, with the really low 1st gear is actually a disadvantage when you are racing.

As for the lockup, when you get to the point when you want to go faster, then the lockup and the 4th gear don't matter.