Just wondering, for future considerations, will my stock 1987 A4 transmission and drivetrain be able to handle 300+RWHP or will it put more wear/strain on it then it was designed to handle? Would it be wise to modify/upgrade both when considering dropping in a much more powerful engine?

 

It would accelerate the wear on the A4. I had mine rebuilt under warranty and it lasted for 6 months behind my 383. Got www.rosslertrans.com to rebuild it and it lasted for 3.5 years.

 

Your 700R4 should be able to handle your horsepower(???) but the 2:73 10-bolt (limited slip??) is probably on its last legs by now
if you have been abusing it. Look for a 9-bolt BW 1989 rear with disc brakes and swap it in.

 

a transgo reprogramming kit, not just the shift kit with good cluctches, hardend sun gear and corvette plantetary with an oil slinger will all make the A4 last longer. for the rearend, a girdle, redline shock proof gear lube, hardend pin,(the 5/16 bolt that holds it together, welding the axle tubes all the way around the center housing and preloading the rearend when you launch it will help alot. the maing problem with the 7.5 is the flex alot, and when they happens they have a tendency to wipe out gears. there are guys running bottom 12's and high 11's on stock 7.5's. Are they as strong as a 8.5 or 9? nope. but you can do some stuff to it to live behind 300 ponies. hope this helps.

 

As far as the tranny part...I had a TCI 700 street fighter way back when the car still had the factory TPI 305, and I destroyed it with 125 hp spray. Im pretty sure it wasnt pushing the 300 whp marker. Im not very fond of the 700 for drag racing, but then again my car is primarily a drag car.

10 bolt should be ok, get a little better gear (3.73?) and stall it up good to pre load the drivetrain before launch and it should hold good behind an auto. Just dont expect it to hold to a trans brake.. The only reason my 10 bolt kept on breaking is I had a m6 in the car and its hard not to shock the drivetrain with a sticky tire out back.