Does anybody know what a 92 rs w/305tbi with a 400turbo would run in the 1/4? And are anythings I need to do before swapping out the 700r4?

 

Likely run the same as it would with a 700R4 in the same condition.

 

Or slightly slower due to heavier weight & greater internal rotating mass.

 

I will second the slower. The turbo 400 robs more power, probably.

 

I'd agree, DEFINITELY slower.

You'll have to alter the crossmember, do something about the torque arm, and have some drive shaft work done. Of course you'd lose your overdrive gear and your "breakaway" 1st gear too.

Lotta maze, little or no cheese at the end.

Now if you had a motor with some power, a big block or something, it might be different. Then, its additional strength might be worthwhile. But with a TBI 305.... I don't think so.

 

I agree you're pulling around more weight,the hassle with mounting the much longer TH400,new driveshaft needed too and less torque mulit in 1st gear,Th400 usually has a 2.30-2.50 vs 3.06 in most 700R4s.With a SBC a well built 700R4 is a the best all around choice IMHO.

 

I think that there comes a time when a decision must be made. Will this car be used for drag racing with limited street time, or be a street car with limited drag time. If its primarily a racer, go with the non-OD trans. Its cheaper to build for more power. If its a street car mainly, keep the overdrive. Or go for the best of both worlds and get a gear vendors OD unit.

 

the 400 that im using is pro built and i have a tpi company stall converter (2500-2800} does this make a difference?

 

Hmmm, let me think here....



Does that move the crossmember in your car from where it is, to where it would need to be? Probably not.

Does it change your drive shaft to the right length, and put the right yoke on it? I doubt it.

Does it add an overdrive? I don't think so.

Does it change the 1st gear to something that will help a gutless TBI 305 launch that heavy car? Well, maybe not.

Does that reduce its weight? Let me get back to you on that.

Does it reduce its parasitic losses? Not likely.

Does any of that provide a torque arm mount? Ummm......

So, you do the math. Does any of that stuff make any difference in terms of either fitting it into your car, or making it more nearly suitable for it?



I think you'd do better to sell it, or save it for some other car where it would be more appropriate; and get your 700 fixed. Most especially, if this car is primarily your daily driver; and even more so, if "you're on a budget". I can easily foresee it taking as much cash to put that thing in that car, as it might take to fix the 700. Or better yet, see if you can figure out for yourself what's wrong with the 700. It might turn out to be something not too hard to deal with, once you conquer the usual layman phobia about automatic transmissions.

I'd suggest as a first step, buy a good manual for it. Go to www.bulkpart.com and get yourself a copy of the ATSG manual for the 700. Worth its weight in gold, even if you don't decide to tackle it yourself.

 

it takes a bit of power just to turn a th400. its un-necessary to run a 400 on a 305 (unless you have an insane twin turbo set up or something and your pushing 500+ HP.) if a 700r4 is out of the question, i would suggest a th350. its a nice street/strip application.

 

Yep, the TH350 is very tough and takes less power to use than a TH400. I'd go for the TH350 before the 400.

 

He would still have the fitment issues listed above with TH350.