there’s something else wrong. The screws in the end carbs are just for idle. As soon as the end carbs open, they should be drawing fuel from the main circuit. Check fuel pressure and make sure your fuel filters( inline or end the inlet of the outboard bowls) are not plugged up. I have a question. What oem end metering plates did you have in the carbs originally. The different plates have different size holes. For instance.
4393 front no 6178
Pass. .080
Dr. .085

4394. Rear no 6180
Pass .084
Dr. .092
Both of these plates have a .034 air bleed in the plate

I’ve got some more notes at the shop but the plates that I checked and recorded on my phone were some old direct connection tuning plates and may not be the same as the oem no. 34 and 35 but here they are.

Front no 34
Pass. .088
Dr. .090

Rear. No 35
Pass. .085
Dr. .093

These plates have .037 air bleeds which will lean the mixture slightly.

Remember. These are actual sizes in inches. The Holley jets are numbered differently. Check the chart you got from Promax. I don’t have it here at my house. If you still have problems, shoot me a pm and I’ll give you my number and you can call.