Motor runs like s--t until it warms up?

Two things:
It's not EFi.
It's a Holley.
Check the chok for battery voltage or very close when the key is in the "run" position. If it's less than 10, figure out why and fix it. Then set the choke timing and high idle speed.
Last, rebuild the carb with an AED kit, clean out the bowls and blow the passages clear, make sure the power valve is properly sized and re-tune the idle mixture. I tell my customers that a carb rebuild is normal maintenance every two years. Sometimes you get more, but most times it's an improvement.