I have a 357 with about 9.8.1 compression running a PAXTON SN-93 and it makes about 6 pounds of boost, I have just recently put it on my car and the car was warming up in my driveway. I rev it a few times checking the basemap on my laptop. I see white smoke coming out of the tailpipes. I figure i blew a head gasket. In fact i cracked a head. I had overheated the car before but i never saw white smoke to make believe i blew a head gasket. I take the heads off and one is cracked. I had the motor running rich so i doubt it detotnated. I was wondering if anyone else running boost has cracked a head especially without any engine load. Also has anyone cracked a head overheating? The heads are L98 heads all done up.

 

my brother's 350 nova was running on 7 cylinders after an overheat on the highway. He tried to run the motor into the ground before he put in a 396. that thing ran strong for like six months (on 7) without a problem and he decided to stay with the small block so we took it apart to see what was wrong. the headgasket was completly gone between the 3 and 5 cylinders, but some how that managed to make the #3 cylinder run stronger to make up for the lack of #5. I was cleaning up the heads later to put them back on the engine and there was a chunk of iron almost completly broken off the driver head right where the head gasket blew. I think it is pretty common to crack a head when you over heat. Its pretty common to blow a head gasket

 

nevermind i got it pressure tested it wasn't a crack it was a little galge in it. I guess i lucked out

 

Oh, and after we saw the crack on the head we checked out the block and it was cracked too, right between the #3 and #5 cylinders. he had it fixed at the machine shop.