Re: how much hp to run th400
A TH400, in stock form, is one of the strongest transmissions made. Using mostly stock parts, they will hold up well to about 750 Ft Lbs of torque. I had a friend with a BBC Caprice convertible who raced it every weekend. For launch, he would rev the engine to 6000 RPM, and pull the column shift lever into "Low". He did that for a year and a half before something broke. Literally hundreds of times. That's when I became a believer in TH 400's. Yes, he did break other things, axles and yokes, etc.
I considered using a TH350 until I talked to Arnie Beswick at a Nostalgia race. He went with one because of the supposed better efficiency, but after blowing up a few of them, switched to a 400 like everyone else was using. No more problems.
406 SB, Original Bill Thomas '63 Rochester FI
AFR 210, Lunati 501C2LUN, 255/263@.050", .628"
10:1, TH400, 3.31's, 4400 SS
"Life is too short to not run a solid roller cam."
"Nothing is impossible; if you don't know what you're talking about."