late model 700r-4?

[DPG_Z28]

Hey everyone-

I consulted a guy in my area who rebuilds tranny's for a living, and I was inquiring about doing a performance rebuild on my 1984 Z28 700r. He denied even looking at it, claiming that anything before I believe 87 had a design flaw somewhere and wont last after a rebuild... Is this guy off his rocks or what? I am nearing 200k on this transmission, it is original, but definately want a new one in to handle a lot of HP and more miles... But it works flawlessly ( knock on wood ). Your help is appreciated.. thanks

[chevymania.com]

The 82-85 700R's had 27 spline input shafts and 86 and up have 30 spline shafts. The 87 was the first year of the auxilary valve body design. This improved oiling and dramaticly improved overdrive clutch and overrun clutch life.

If I were to build a performance overdrive I would use a 90-94 4L60 (non electronic) from either a truck or a camaro/vette. I would use the 2002 5 pin planet gears and a bunch of aftermarket parts.

I have built 85 model 700R's for performance but the 87 and newer versions are much more durable.