Holley Carb problem

While the intake may not be the main cause of the problem, it can make it difficult to tune the carb because of the mismatch with everything else. A good dual plane intake will make it more responsive. In theory, the big intake will reduce the vacuum signal to the carb and can require bigger jets, squirters, lower power valve and lighter secondary spring than with a dual plane.

OEM primary jets were 72 and the secondary plate is equal to a 75 or 76 jet. That's what you would start with if you have/get the secondary metering block conversion. OEM power valve was a 6.5 and squirter was a .031. Maybe the pump cam is too big and make sure the power valve isn't blown. I don't recall what pump cam they came with.