Im getting ready to do studs and a gasket. My first question is, do i need to have the head o ringed? I dont plan on going over 60 psi at most and more than 5 or 550 hp. And my second question is do i HAVE to have the head milled flat? I was told i only had to do that if the engine had ever been over heated.

Thanks!

 

You don't have to have the head o-ringed, but might not be a bad idea. If you're going to pull the head, you should definitely have it at least checked for flatness. 12 valve heads very commonly warp even if it's never been overheated.

 

Ok. Thanks. Do you know what an o ringing job might cost?

 

you can check the head your self take a straight edge and use a feeler gauag to see if its warped.

 

And just use a marine gasket with stud, many guys int he 600HP range just have Marine Gaskets and studs, no o-rings

 

my o ring job cost me 240 bucks. decking the head machining and intalling rings along with machining the rockers. cheap insurance. you might as well if the head is off.

 

o-ringing the head, ASSuming it is already flat and does not need to be decked, can range from $40-60 per cyl. and that should include cutting the head and the wire ring

 

The .020 over marine gasket lowers your compression. That makes it harder to start, it smokes more, and you'll have less power. It should only be done if you have a good reason to do so, like the block has been milled. It's something to be avoided on a street truck, especially in you live in the cold weather states.

The high hp trucks that have done it, do it because they're running crazy high boost and/or timing and aren't too worried about starting, smoke and etc.

 

Just did the math and the .020 over gasket actually lowers the compression from 17.0-1
to 15.86-1 Holy Crap I didnt think it was that much they took .007" off my head when it got surfaced so im at 16.25-1 it still starts good at 0 degrees tho, just figured I would share my findings.