Prime to start.

[39topless]

I have installed two 97's, that I rebuilt, in a 2 X 2 setup on my stock '39 V8. The only way to get this started is to prime the carbs. I have also installed a new electric fuel pump that is run through a new regulator that was factory set to 2.5. I do start the pump for about 5 seconds before turning the engine over. Do the idle adjustment screws have an effect on the startup? They are set to about 3.5 turns out. What should I try?
Thanks, Phil