[MARKDTN]

You have to ask yourself why GM never used a 200R4 behind anything bigger than a 307 Olds. No Corvettes, no big blocks, not even a 305 IROC. 200R4 was used in the Turbo Regals and GNs, but they don't last long there after engine mods. True, the GN was the highest performance application stock but in truth the 200R4 in stock form is not all that strong. They do require a rebuild to use much power or you will shatter the insides. If you are going to build the 200R4 first then fine, just don't yank a used one out and expect it to last in a truck. They were never used in a Corvette with the CrossFire (205HP/290 Torque) or TPI IROC (195HP/295 torque) which was about the same power as a stock GN (200HP/300 torque)-much less a 250HP TPI Corvette.

I'm not saying don't use a 200R4. I am saying that it might not last long if you take a used one out of a tired V6 or 305 A-Body and put it in a heavy truck with a 350/350 and trounce on it. I would do a 700R4. They got a bad reputation from early on, but if you get an '88 up core with the improved guts they last a long time. They also get a bad rap for swaps for people that didn't adjust the TV cable and burn them up fast. You should not start the engine until the TV cable is properly adjusted!! It is that important. The 4L60E that is still used today is a derivative of the 700R4 and they last a long time. I have one in my '01 Tahoe with 299K miles that has never been out. The 200R4 can be built to handle the power for sure, but a 700R4 can do it with a lot less mods. The current 4L60E shares some internals with some of the last 700R4 (4L60) transmissions.