i have 2 SBC questions having to deal with HP

[eurodad]

@slvr98camaro

yeah, but we cant get it tuned right, the idle mixture screws on the carb dont seem to work, checked for vacuum leaks and found none, checked the vacuum and it seemed good, and the carb was rebuilt.

(the carb is a holley 600cfm, but i plan on getting a 750)

how much vacuum is the motor making at idle?