I have been plagued with exhaust manifleaks on my 1970 360 motor, I pulled the heads and had the exhaust surface machined, and the manifolds resurfaced, and torqued all back down properly, but am still getting leaks where the manifold meets the head, the gasket blows out after awhile, any ideas?, thanks, Doug

 

Both surfaces re-machined and still got leaks? I'd question the machinist myself. You might try a premium grade gasket and see if it lasts any longer but based on that info, leaks in that area should be virtually non-existant.

 

You might try some of the Copper gasket sealer.

 

id try a copper gasket, and either gasket sealer or some RTV sealant

 

i had good luck with the victor nitroseal gaskets at napa.

 

What kind of gaskets are you using? I believe that Felpro makes metal stamped gaskets with raised areas around the ports. These may be worth a try. I would also use stainless steel fasteners with a metal based anti-seize compound and then torque everything to factory specs. Another thing to look at may be the timing depending on the year of your engine. If the ignition timing is to retarded, a lot of the fuel will still be burning in the exhaust manifolds which will really heat them up and cause warpage.

 

I'd go with what BigRed says, I did all the differant gaskets and machine work on my 428 and finaly someone told me about the metal heat shield gaskets from Fel-Pro and they have been working now for 3 years without blowing.