Drag Racing Online: The Magazine

Volume VIII, Issue 4, Page



Hi, I'm on my 3rd 700r4. They keep wiping out 3rd+overdrive. My car is a nearly stock 93 Z/28 exhaust and chip are all the mods. Now I'm sure your thinking he's probably beating the car pretty hard. I have bracket raced it, and entered several burnout contests. But this is my daily transportation so these are isolated incidents.

My friends are telling me from they're experiences that these trannys are junk. Can I swap in a Turbo 400? Or should I have the 700 redone as heavy duty as possible? Whats involved in the 400 swap? Just the yoke? Or will I have to modify the trans mount as well.

Thanks for your help.

Joe Waite
Lansdale Pa.


1993 was a transition year for GM from the 700R4 tot he 4L60E. Either transmission can be modified to take 300-400 horsepower. But you need to identify which one you have. The 700 R4 will have a conrol cable from the throttle body to the transmission. The 4L60E can be adjusted through the computer possibly with a chip. The 700R4 transmission needs to have the cable adjusted with the aid of a pressure gauge. These units should hold up for what you are doing if all systems are good. Installing a TH400 transmission would be good for a race only situation but not on a computer controlled highway vehicle.

#1-You would lose your overdrive, which means 25-30% worse fuel economy from the extra thousand RPM you will be running on the highway. #2- The computer on your car monitors the transmission whether it is the 700R4 or 4L60E. It would not be able to monitor the TH400. So, you would get a check engine code or check engine light on the dash. Fixing the original transmission would be the better idea.

Build another car for bracket racing and burn out contests, your commuter car will be happier.

Thank you for your questions,


Mike’s Transmission
Lancaster CA
(661) 723-0081


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