Sorry to get in on this so late, but I have some feedback for you on Transmission Center, Inc. I live near Bossier City where these guys are located. I talked with them about what I wanted and how the truck would be used and 3 years ago they built a 700 for me that went in a 4 wheel drive 88 suburban 1/2 ton. The truck was used hard in the lignite mines in east Texas as a work vehicle. The transmission performed flawlessly and still is doing well to this date. I sold the truck last year to a local guy who uses it pretty hard all fall and winter in his deer camp.
One thing I had done on this trans was a 1 wire torque converter lockup in 4th gear (od) only. Wired the lockup with a toggle switch and indicator light and only hooked up convertor at highway speeds.
Also have a 84 S-10 with a 350 and a 700R4. Trans was built by Mike Mains in Shreveport, LA. It too has the one wire lockup and is valved to not let transmission shift down once in overdrive when you stand on it. This transmission has performed flawlessly for 4 years of fairly hard use. Motor in this truck is probably 300 - 320 hp although I have no scientific proof like a dyno test. Just what the heads, induction, exhaust and cam would theoretically give.
Point of all this is... Based on my experience a properly prepared 700R4 is probably exactly what you're looking for.
Bob
