460 Overheating problem
I have a 1973 F150 ford Pickup engine was completely rebuilt bored .30 block vated ,cam bearing, and new core plugs block was power washed after vatting, Heads baked surfaced new valves and spring retainers .10 taken off head for cleanup pistons are stock flat tops, stock iron intake,carb, stock exhaust and duals, cam is a comp cam for rv use, new lifters,push rods and rockers, new timing cover, water pump, fuel pump, new fan clutch 6 blade fan , new HD rad and new fan shroud , rad cap and coolant recovery system.
Engine is started cold on fast idle as soon as the choke will allow slow down engine idles at 750 rpm automatic trans, ps,ac, new thermostat 190 degrees, timing set without vac advance at 6 degrees, when connected and engine reved timing goes to full advance at about 3000 rpm of 28 degrees, engine starts easy no pinging or back firing, after 10 to 15 min of idling temp heads for hot and at 20 min gauge is almost pegged no running after starts really climbing, no cyl missing, no spark knock no other noises, ,no water in oil, no water out exhaust, and no hydro carbons in rad,
WE just replaced thermostat with another 190 still same problem over heating.. We are beginning to think head gasket might be installed upside down restricting coolant flow but no enough experience with 460 to know if it matters we used fel pro gaskets.
Any help would be gret we are running out of ideas before pulling motor and pulling it down, could timing cover be a problem? also new rad cap
Thanks for any help