Overheating even after the shop

[87SunSportMikeyD]

I just learned that the OEM water pumps should pump 9 gallons per minute. My original pump came nowhere close to that, maybe a couple gallons a minute. Tried tons of stuff, and eventually replaced the whole water pump. Worked for me.

Your new problems do sound to me (amateur) like a carb issue, but could need adjustment, a good cleaning, or a rebuild (new seals, etc). There is a quick check you can do on the "power valve" on holleys website if you google it. Have you ever had the engine compression tested? Good luck

[Kma4444]

I'd say fuel delivery. If it initially accelerates well then starts to cough it sounds like the float bowls are getting low. Check fuel filter(s). That really means change them if they haven't been changed recently. Then do a fuel delivery check on the pump. You will pull the fuel line off at the carb or somewhere after the filters and run a line to a container and see what you have for volume when cranking the engine. You should get a good shot of fuel every other engine revolution, no need to count engine revolutions btw. Just look for a good pulse of fuel and you should get a pretty good volume of fuel in say 15 seconds of cranking. I'm guessing a cup or so. What you want to be sure of is that it doesn't just pump a little bit and then barely trickle, if it does you have a restriction in the supply side of the system.