I've had 350 and 400 TH trannys run for 250K, then yank 'em out and put 'em in something else, replace the filter, and put another 250K on 'em.

I haven't ever had a 700R4 (and the oldest one I ever had was a '86) last for more than 130K without needing a full rebuild.

And when it comes to parts and buying the tranny in the first place, the 350 and 400 TH's has the 700R4 beat hands down.

an idea is only stupid if you think about it rationally.