BEST OVERDRIVE GM TRANNY

[qjetsrule]

OUT OF THE TWO COMMON GM OD AUTOMATIC TRANSMISSIONS, THE 200R4 AND THE 700R4, IS ONE TRANSMISSION BETTER FOR HIGH PERFORMANCE. THE ENGINE WOULD BE A 454 CHEVY APPROX 500HP AND 550 FT LB TORQUE.

[Cliff Ruggles]

Without hard parts upgrades a 1987 or later 4L60.  The 200 is a weak unit in stock form.  Even 1986 and later GN units need hard parts upgrades to live behind that kind of power.  The 200's get some good press once you fill them with billet internals, but I would NOT use one simply rebuilt with a shift kit and GN servo, etc, behind a big block making that much power.

Back around 2001 we built a 4L60 for a 454 powered Chevelle.  It has been driven many thousands of street miles and raced frequently.  The car runs low 12's in street trim.  A few years ago the owner hurt the engine and brought the transmission in while the engine was out to "freshen it up".  It really didn't need anything.  We replaced the 3-4 clutch pack with the later high energy frictions/steels, a few new seals and gaskets and sent it back.  Still going strong behind the new stroked 454 making even more power....Cliff

[Bob1966]

Cliff,
Picked up your book on overdrive tranys, great information. I am looking to upgrade my 4x4 turbo 350 with 205 transfercase to a overdrive unit without electronics. You mention a 4L60 from 87 on would be a good unit to look for. Will the transfer case adapter from the 350 fit the 4L60 or 700r4? Is the 700R4 the same as 4L60? Also except for the transfer case if looking for a unit at the junk yards would there be a diffeence between truck or car units? This is for a stock suburban no heavy off road use or big tires but will be towing a 20' ski boat.
Thanks
Bob

[Cliff Ruggles]

87 and newer 4L60 before they went to the 4L60E.  Some folks still call them 700-R4's, same thing.

It would need to be from a 4 X 4 to have the shorter output shaft to use in a 4 X 4 application....Cliff