The 390 CFM (list #8007) has .038" PVCR.
The normal sequence is to find the best main jet for mileage first.
Then, test the WOT the easiest way by using a larger main jet (yes, this will temporarily ruin mileage) so you don't have to modify the PVCR more than you need to.
Go up in main jet until your 1/4 mile speed does not increase (last change = no result).
Now reduce the size by 1 at a time and test.
When it starts going down, STOP. Add 1 to the jet number.
Now you have the total of MJ + PVCR "best power" area.
Calculate the MJ area: jet ID (not the size!)^2 * 1.5708. Example: .060" jet area is .00565"
Add the existing PVCR area: .038^2 * 1.5708 = .00227".
Total area is .00792".
Subtract the "best mileage" jet area, example .056" = .00493".
The result is the new PVCR area, .00299".
Divide by 1.5708, then take the square root.
The PVCR should be drilled to .043" (#57 drill).
Now, put the mileage MJ back in.
