1point3liter

I have a set of #317 casting 6 liter aluminum heads and will be running either a 3.902 or 3.905 bore. Boosted obviously..

Some people seem to like the layed 4.040 bore GM gaskets

Others say go with cometics.

I'd prefer the thickness to be around .055 - .060

What headgaskets have you guys had luck with on similar setups?

MECHAM

iTrader: (4)

cometic 3.910 bore

1point3liter

Will they interfere with combustion chamber size of the 6 liter heads?

Anyone know the compressed thickness?

99Fbody99

GM MLS (Multi Layer Steel) gaskets by far.. and there cheap, less that $30 a pair..Even Harlan runs them still

Dave

Pro Stock John

iTrader: (34)

I am:

6.0 heads
6.0 MLS head gaskets
3.905 bore LS6 block

1point3liter

I looked back and found someone claiming they were 1.33mm compressed thickness. That converts to .052

Can anyone confirm this?

Part numbers?

TIA.

Speedfab

Get off internet, weld heads to block. That will make your thickness somewhere around .000

MYTURBOT/A

You have to use the 6.0 bore gasket or they will leak. the compressed thickness according to GM is .055 on the stock 01 up MLS gasket.

MelloYellow

Have had nothing but problems with Cometic Gaskets lately. I wouldn't touch them with a 10 ft pole. Am switching to GM MLS now.

I forget the 5.7L bore size. I've heard different bores quoted.
6.0L MLS bore above per PSJ I believe.

smokinHawk

iTrader: (48)

must use a 4" bore gasket with the 6.0 heads unless you want them to leak.

i had trouble with my first set of cometics, but this one i have on now is doing alright.

If you dont need a specific thickness/GM thickness would work for you , get them
if you need a specific thickness use the cometics.

1point3liter

"oooooh we can fix that"

1point3liter

Thanks guys,

My compression ratio will work out to 8.5:1 with the .054 compressed height 6.0MLS gaskets so I'll stick with them.

This is off topic with my orginal question, but how many of you are using ARP main studs? At $160 or so dollars are they worth looking into?

Pro Stock John

iTrader: (34)

I am using ARP main studs and those fancier H11 head studs made by someone else.

smokinHawk

iTrader: (48)

im using them.
i think there good insurance.

1point3liter

Who makes the H11 head studs? What's different about them?