Engine Cooling problem
1985 Pontiac Parisienne V8 Two Wheel Drive Automatic 170000 miles
I have some major over-heating problems with my 85 Pontiac Parisienne. I recently had an engine swap, both are 305 chevys, so quick change there. Now I'm running in to the heating. I have replaced the entire cooling system down to the radiator cap. I also replaced, far as I know, the whole distributor setup including new plugs and wires. Almost everything under the hood now is new or newish. I had someone say it maybe the catalytic converter, it might be clogged up somehow and the exhaust flow is just circling back to the block build heat faster. There also seems to be some sort of butterfly valve on one side of the manifold that appears to be shut also. I'm just needing input and advice. Thanks.