I really don't understand why so many people here say it's more trouble than it's worth. I put a 700r4 in my 68' chevelle by myself when I was 16 years old. I got it out of an 87' IROC from a junkyard for $500. It worked PERFECT behind 400hp for years until I sold it. I will be putting one in my 67' SWB, and every other car I build.
For me, not being able to cruise 90mph(@LOWrpms) on the highway is WAY more trouble than bolting in a trans, shortening the driveshaft, adjusting the tv cable and wiring up a toggle for 4th gear lock-up. (I don't recommend a toggle now, that's just what I used back then)
I would guess that most of the people against this mod have never even tried it, but only heard a few horror stories about guys burning them up, usually from a improperly adjusted tv cable or not having it hooked up at all.
A properly installed 700r4 will work just like it does from the factory.
This mod is VERY easy to do and well worth it!
Just my $.02