I have a 1992 chevy 1500 with a 600 holly carb I'm 200 miles sense the new engin and it died on my at a stop sign and now it won't stay running under 1000 rpm. The carb backfired but started up 10 min
Holly carbs don't like it when the engine backfires. It usually ruins what we called the "power valve" diaphragm. This makes it hard to keep the engine running. I personally dislike Holleys for this and other reasons. I'd put the QuadraJet back on and get some reliability.