I've gotta 700R4 in my 53 as well, an '87, which gets beaten regular. I've had several 'R4's tru the years, once you rebuild them they seem to go forever. Now that I'm used to the lower first gear plus the advantage of overdrive I'll never own another 350 or 400 tranny again. BTW, I've seen plenty of 350 trannys burn up, nothing lasts forever...
