Im looking for an auto transmission that can handle a modified 20b with close to 700whp. Im looking for the car to be a driver, road course, and strip car all at once, so something that has a great overall performance would be best. Ive been doing searches, but havent seen a ton of options. let me know what you think

 

Maybe a GM 4L80E (TH400 with overdrive). They weigh well over 200lbs and are physically very large. Built up it would be dead nuts reliable (many racers putting down 1000rwhp in 5,000lb trucks drag racing with these. but not sure how it would hold up to road race abuse.

Any reason you don't want to put a manual transmission behind that setup? I can't think of any reasons why you wouldn't......

T-56 (6 speed manual) could handle the power and keep fuel economy in check:
http://www.libertysgears.com/faceplate.htm

http://www.gforcetransmissions.com/tran_gt-56.asp

 

Auto is the wrong choice IMO. The HP loss on a 4l80-E is MASSIVE, and a pretty penny to modifiy to be worth a crap if you can even find a way to bolt it up to begin with. Any auto tranny is far heavier then any manaul as well. Why are you wanting an AT anyway?

 

For about $5K you can have a bulletproof 4L80E. They suck up somewhere around 50-80hp; however are dead nuts reliable being based off of the infamous TH400. You could also put a Gear Vendors overdrive behind a TH400 or even a TH350 depending upon what your car weighs.

I would not put any automatic behind that setup. Go manual for sure.

 

there is a specific reason that i really dont want to get into why I want an auto, thanks for the responses so far

 

so thats all the responses? I guess there arent many options

 

Free bump and ...

I've heard several times that the 4L80E tranny won't fit in the FD tunnel. Check with Granny's or Hinsons, I bet they have heard this question many many times.

Maybe go with a 4L60E that is built for the extra HP.