What jet and pv size on a 4150HP on SB?

I'll just leave it at, "You'll need to play around with it" rather than tell you what I think since everyone has an opion of what intail should be.

I followed the MP books advice and it works fine for me.

If I'm racing at the track, that's a different story. And so is the octane available.

My old street racer cars were basic bombers built on a poor mans budget. I used to run them without a vacuum advance with as much intial as possible. Things got really interesting when I was given a MSD start retard box and ran a locked out lean burn distributor.

If the total timing stays the same, then I do not think you'll need to change octane. But to much intail could require more octane to prevent the pining. IF it pings with to much intail, then I say you went to far.