I have a 90mm TB on my 422. I'm not saying that it can't be tuned, only that it will be much easier with a smaller TB. With a big one like that, very small throttle angles flow a TON of cfm, and can make throttle tip-in a bit annoying. It can be very jumpy and may tend to buck.
A guy in Tucson made 1033 rwhp with a TT 337 and an 85mm TB. I saw a guy in a magazine make over 900 rwhp with an 75mm TB. When the intake is pressurized, it overcomes many restrictions and the TB and intake runner size becomes less critical in the overall picture.
Anyway, that's my advice - take it or leave it.
Paul.
A guy in Tucson made 1033 rwhp with a TT 337 and an 85mm TB. I saw a guy in a magazine make over 900 rwhp with an 75mm TB. When the intake is pressurized, it overcomes many restrictions and the TB and intake runner size becomes less critical in the overall picture.
Anyway, that's my advice - take it or leave it.
Paul.