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

Check the vacuum with the car at idle in gear with your foot on the brake if you have an auto trans. Note the reading, divide it by two and that will be your correct PV size.

http://www.holley.com/data/TechService/Technical/power_valves.pdf

Holley has a wealth of tuning info on their website:

http://www.holley.com/TechService/Library.asp