dieseldork

Getting ready to pull my head off to put on a new head gasket and ARP studs and was wondering how many of you get the head resurfaced when you pull the head off . How do I tell if I need to do it ?

Bjans

i would just to make sure! have a machine shop magnaflux it and make sure it has no cracks and have them true up the head surface if its out a bit

Fishin2Deep4U

I check everyone for flatness when they come off. Almost always they need to be machined.

Dave

logskidder

Have the head checked for flatness.......they almost always need a little taken off.

HOHN

I'd think it unwise to have the head off an NOT have it machined flat.

Not only do you want it nice and flat, but I'd put on the finest RA finish your shop can accurately and affordably achieve.

jmo

RowJ

Ditto!
Factory heads come new...as much as .015 variation in flatness. That's probably flat enough for factory power but not if your adding a couple of hundred hp (plus)!

RJ

dieseldork

OK then I will probably better plan on getting it done . Anything else I should do or look for while I have it off ?

logskidder

Depending on your goals, you may want to have the head cut for orings.

dieseldork

My plan is to use a 3rd gen gasket it is a multi layer one . I have a friend pushing 80 psi with twins with no problems using one .

RowJ

If it's the Cometic gasket (3rd Gen designed for 2nd Gens), your friend is the exception to the rule.
Those gaskets have been pulled from production because they were failing often.
2nd Gen block is not smooth enough to seal the 3rd gen gasket well.
I just went through this 2 months ago when I needed a new head.
O-rings, and a marine gasket (.020 over stock thickness) is the system that appears to be working best ... assuming they take .010 to .015 off your head.

RJ

dieseldork

This gasket I have is a cummins 3rd gen gasket .
So what do you mean by a 2nd gen block is not smooth enough to seal the 3rd gen gasket well ? Is there a difference between a 2nd gen an 3rd gen block ?