Ford 351, 390 main jet sizes

Hi all!

I would like to know if anybody has any experience for the correct jetting for my two engine.
I have a 600 cfm Holley vac sec for both engines.

1.,
stock 351 cobrajet except electronic ignition, carb, and a performer intake.

1.,
390 FE, edelbrock streetmaster intake, carb, unilite distributor and compcam XE262 cam.

I have 64 main jets for the cobrajet, but I think it's too small.
The 390 has 70 main jets, maybe it's correct, but when I cruise and hit the throttle pedal to the floor it's hesitate.

 

Your close on the 390.check the timing and the acc pump.351 needs more.try 70-72 first.remember,if you advance the timing you lean the mixture.351c likes alot of lead timing.good luck

 

Do you mean 351 needs bigger main jets? I have 68 installed now but I have not check the plugs yet.
And what about the secondaries with the 351?
The 390's carb has a plate at the secondaries, but on the 351 I installed a conversion kit and I can change the secondaries' jets.