I have the propane flow meter from tidewater I flow at 40 inches and the air gauge is at 7.8 normally 6 to 7 is the norm for a .45 but there are a lot of variances my .45 vac with port work .008 on the head clearence and stock timing runs best at 7.8 to 8.0 with a nitro pipe set at 9 1/4 to 9 1/2