I see that their are mixed emotions about these transmissions. The 93 Z i just bought has 1 in it that was rebuilt with a 2500 stall. I feel like when it is going thru the gears under heavy throttle it is slipping out of gear and slipping into the next gear. I read that these transmission are mainly used for the O/D and fuel mileage. I did not buy this car for fuel mileage, so if that's how the shifting is going to be i'm taking it out! I'm looking for something that shifts now! could it be the stall that is causing the delay and rpm rise between shifts? car is currently putting 467hp with 507ft lbs of torque to the rear tires. needs new supercharger belt and tuning after new belt and sparkplugs.

 

A properly built 700R4 shouldn't shift that way. We have them running in the low 10's. If modified correctly, the shifts can be very impressive. The 700 has a few other benefits over other automatics. You've already mentioned the overdrive, but a 700/4L60E has a 3.06 first gear ratio. The lower ratio will usually enable the car to launch harder. A 700 also takes less HP to turn than a TH400, so the car will usually be quicker with a 700. Trying to swap anything else in can be expensive because you have to modify or replace other pieces, such as driveshaft, converter, crossmember, and torque arm mount.

Frank

 

could it be the stall convertor making it shift bad? its a gradual shift vs shifting now!

 

2500 isn't alot of stall. Yes, the more stall you go with, the softer the shifts will be, but if the transmission is properly built, you can compensate for that. We have 700's with over 3500 stall that still chirp 2nd and 3rd.

Frank