Cam/Head Swap Disaster.......

I would "guess" either intake manifold or timing cover sealing issue. Or both. Tell us about the heads. Rebuilt I assume? Have they been pressure tested or magnafluxed?

Lastly,WHAT engine are you working on here?
This is on a 360 in my d100. The heads were bought from a member here, though I didn’t do more that completely strip them, inspect and replace accordingly. I had the intake milled to cleaned up as as well as the heads. Everything lined up fine, no struggle on that. I’m just really confused because the radiator still has water in it because it didn’t get hot enough to open the thermostat.

Jake