I have a 267 in a 79 El Camino that is giving me some weird issues. I had it apart to replace some leaking gaskets. While I had it apart I added a Summit Racing cam, new timing chain, factory quadajet intake and a Q-Jet. It also has true dual exhaust with headers leading into 2.5 inch pipe. My problem is that I can’t get it idle below 1000 -1400 RPM. Also it won’t rev up past 2500 RPM. I changed the fuel pump, but that didn’t do anything at all. Same problem at the same time. Any ideas on what it could be?