Badlybent

Doing an LY6 build. Deleting VVT, going to be using LS3 intake and doing a cam swap. I plan on milling the heads .020" to up the compression a little. My question is what head gaskets to use as far as bore size and thickness. Any help would be awesome. Thanks.

87silverbullet

iTrader: (11)

That all depends on choice of cam. If you shave the heads you might run into PTV clearance issues. I'd run a thinner gasket instead of shaving the heads. You can get a .040 cometic to take it down from the .051 stock gasket. That alone should almost raise your compression 1 point.

COSPEED2

iTrader: (7)

You can either use the stock LS3 head gaskets which we carry, or you can get a cometic 4.085 x .045 which we have also. I would not use a .040 as you may run into issues. You will DEF need to measure your pushrod length with that much milling. We have the Comp Cams pushrod measuring too here.

Briou

iTrader: (1)

Not trying to thread jack, but does anyone have any suggestions as to what head gasket to go with for a 454cid ls3.....I am planning on using a 4.200" bore by 0.051" thickness...the bore on the cylinder is 4.185"....I really just need opinions on what brand to go with...

87silverbullet

iTrader: (11)

What is your intentions for this motor? Street cruiser occasional street romp and at the track on the motor, or will it see a healthy hit of spray?

Briou

iTrader: (1)

Mine is going to be a 700hp at the flywheel street/strip motor...N/A no Nitrous....Just looking for the best, most reliable head gasket

Prorac1

iTrader: (4)

Keep in mind that the factory piston pops .005-.007 out of the hole, so this will effect your quench area and head gasket selection. Just things to keep in mind. FWIW, I shaved my heads .030 and used a factory .051 head gasket. My pistons measured .005 out of the hole for a "safe" quench area of .046. I have read many threads of people running quench as tight as .030 and getting away with it, it just isn't what I feel comfortable doing. Hope this helps, Eric L

Briou

iTrader: (1)

This is a built short block from ERL...I will have between 0 and 0.002" out the hole

COSPEED2

iTrader: (7)

Cometic. We have em.

Briou

iTrader: (1)

Any other opinions out there?

87silverbullet

iTrader: (11)

Since you are on the motor a simple set of Fel Pros will do the job.

COSPEED2

iTrader: (7)

The fel pros for that 4.200 bore will be more than the cometics. I am not sure how you are getting an LS3 in a 4.200 bore, my guess is sleeving, but that sure doesnt leave a whole lot of meat between the cyls either.

And the stock replacement fel pro gaskets are trash. Period.

Badlybent

Well, this thread turned out to be quite a conversation lol. I dont have to mill my heads, just thought i would but if i can go with just a thinner head gasket to achieve the same thing, then that would probably be a better route to go maybe. I dont know. As far as the cam, i was TSP recommended a 225/230 so figured id go with that. The engine is gonig in a 54 chevy 210 2 door club coupe. Just gonna be more or less a cruiser with the occasional romp lol.

Badlybent

SO, now i guess the question is, mill the heads, or get thinner gaskets? Whats the benifits of doing it one way or the other. Pros and cons per say.

COSPEED2

iTrader: (7)

If you are using the 317 heads mill them .020 and use the .045 gasket, but be careful on the LSA you choose and the duration. We have a really nice lobe that will make killer power and still have good PTV.
You will get more CR and better quench, instead of just doing one or the other. Make the gasket tight on teh 6.0 at 4.010 and you will have plenty of compression to play with. An LSA of around 112-113 should make for alot of tq just stay down on the exhaust duration.

Badlybent

Thanks for all the input.

Hardcoresoldier

iTrader: (2)

not trying to hijack, but I'm not sure which head gaskets I should go with either.....LS2 block (4.005" bore) with LS3 heads milled .036. I know I want a .035 head gasket to cut down on the quench area to help prevent detonation, just don't know what bore size head gasket to get. It will be a Cometic though. Engine will be 550ish rwhp NA with an occasional nitrous use (somewhere between a 100-250 shot).

Briou

iTrader: (1)

Sorry about that Badlybent...didn't mean to jack your thread

COSPEED2

iTrader: (7)

You shouldnt mill those heads that much with nitrous involved and you really dont want to use an .035 gasket. .045 and 4.015-4.020 is the least you should go. Head studs are a must also. And hd bearings on the crank and rods are a must. That nitrous will hammer the stock gm ones good and you wont want to find out what happens after that. Plus arp rod bolts. If you follow that guideline it should be worry free.

Hardcoresoldier

iTrader: (2)

I have Callies Compstar crank and rods, Wiseco pistons, Wiseco rings with a steel top ring, ARP head and main studs, ARP 2000 rod bolts, ALC bearings. I need a .035 head gasket to get the compression ratio I want or I have to have the heads milled a lot more. If I end up needing to run some C16 with the nitrous then I will just get a stand alone fuel system. I am not set on how much I will be spraying, I will start at 100 and see what kind of times I run. Once I hit my target time I won't need to spray more than that lol.