[YellowK5]

Which carb do you have? I just went through all of the same issues with my 71 350..Edlebrock carb..I installed a new exhaust and welded in O2 bungs so I could use sensors to set it up. The main issue was I had to swap out the metering rods. they were too lean for high vacuum I tried just the springs first but it just made it run real bad..Then i had to install slightly larger main jets..now it is the best running 350 I have driven..which is pretty good for a crate motor installed in 1988