[nick]

its a 1969 383 roadrunner engine. before i bought it the guy started the engine(just idling) about 3 times for 5 minutes with very little water. the radiator is building presure. How should I check the heads out? I don't want to spend a lot of money on them when I could others for cheaper. What else would cause this?

[KULTULZ]

If you think you have an exhaust leak (blown head gasket) into the cooling system, there is a special service tool made (Snap-On/MAC) that uses a chemical that is held in a bulb over the radiator opening while running that will change color when exposed to exhaust gas.

You may also perform a cooling system pressure check (both hot and cold) to see if there is pressure loss.

The only repair is to remove the heads, have them pressure checked and milled, and gasket replacement.

[carnutjoef]

When the head gasket let go on my 5.0 Merc, the first sign was air bubbles showing up in the radiator. The car was also using water with no leaks on the ground. As the last reply the only way out is to get the heads milled, at which point you may as well have them rebuilt. Good Luck, The Car Nut Joe