Cometic MLS headgasket, some questions

[blownhemi]

Does that sticky from 2005 about Cometic MLS headgaskets being problematic still hold true? According to this, zerothread?id=477587, it is not actually true anymore... a little confusing. If Cometic MLS HGs are actually fine, maybe the sticky could use an update with an explanation and emphasis on the right block preparations, maybe some newbies still read that...

- HG bore size (still Cometic)... I can't really make sense of the bore sizes, the standalone headgasket is specified as having a 85mm bore, but the one in the top end gasket kit specifies a 84mm. Is that it? If I order the kit, I get the 84mm one, if the standalone, I get the 85mm one? Any experience?

[bentvalves]

dang, there is even a sticky from 05 about cometic hg's and their inherent problems, imagine that.

i wasnt even aware of this sticky, and I still say stay away from them.

[float_6969]

Here is the deal. A lot of company's make metal HG's. None, of the other companies have trouble with sealing that the Cometics do. This could be due to a lot of things, one possibly being that the other HG's cost more, and so the people that buy them are more apt to follow the directions explicitly and not cut corners. That being said, Cometic VERY clearly states, that when you install their HG, BOTH the head AND block HAVE to be resurfaced, be perfectly flat, and the surface finish of both the head and block HAS to be 50 RA (Roughness Average) or FINER.

AFAIK, everyone who's followed the instructions provided by Cometic, hasn't had any problems with them sealing.

[float_6969]

FAQ updated.

[RS12Turbo]

No probs with mine.....I'm also using oem head bolts.

We should take a poll....seems like I remember reading people that have cometic hg's that use oem head bolts don't have any issues...but people that use arp studs have leaking issues

[Margus]

Same here, using oem bolts and no problems. Why do you guys use arp, no need at all

[sjbsuperman1425]

Same here, using oem bolts and no problems. Why do you guys use arp, no need at all

reusable. I'm not going to risk all the work with reusing stock headbolt and i dont wanna spend $50 everytime I take the head off. i got my ARP's for $80 shipped BNIB from Summit