hello eveyone, I HAVE SEARCHED

so heres my problem..

what i have i have 64 cc heads and a stock head gasket, which i dont know what the thickness is.

what i am getting 65cc heads (195 afr street elemenator heads)

what i want/need a head gasket that will give me 10:5:1 but not over!
right now i have a L98 350 {from a 87 camaro}with headman headers

Im looking to ditch stock heads cam and intake . I am going to order my heads, right after I find out what gasket I need.

~thanks for the help~ if i left anythign important out let me know please

 

You'd be better served if you measure how far down the pistons are in the hole and get a head gasket that gives you .040" quench, instead of trying to tailor CR with the head gasket thickness.

 

excuse me for not knowing this but how do i check the pistons when they are at BDC and TDs { top and bottom dead center )

 

Rotate the engine until one of the pistons is at the very top of it's stroke. Place a straight edge across the cylinder. Take a feeler gauge and stick it between the piston and the straight edge. Adjust your feeler gauge until you get a perfect fit.
FYI - stock is about .0025

 

so i can't do this when engine is in?

 

Stock deck clearance is about .025", not .0025" .... the dancing decimal point claims another victim!

I guess that depends on what it's "in"?

If all it's "in" is a car, then it shouldn't be a problem.

 

If the rotating assembly is stock or to stock spec, you will need a .015" gasket for perfect quench (stock .025 + .015 = .040). The only way to properly increase the compression ratio without modifying the rotating assembly or block is to mill the heads down. Usually the intake needs to be milled as well so that it properly fits the milled heads.

I had the same problem, but fortunately I had a bare block on a stand and could take it to a shop for a 0-deck job. Using aluminum heads with that thin of a gasket will increase the chances of a leak in the future, so make sure you use a good sealant when you install them.

 

no i mean like its is as running and operating ....my car is driven daily thats what i mean.

 

there is absolutly no way to measure with enough accuracy if the engine is in "running" condition

 

arg.....!@#$^% hmm now what?

 

my guess would be there isnt a headgasket out there that will bring low 9CR to 10.5:1 and not be made out of pure unubtainium... here is what you do... order a couple different head gaskets just before you are ready so they show up maybe a day before... when you are ready to do the swap, tear the engine down break out what ever means of measuring you will be using...dial indicator and mag base... measure use the corresponding gasket set to give you a quench of about .040... however in a stock bottom end... you will probably find that a .015 compressed thickness gasket would be required to get even close to .040 quench which isnt recommended with Aluminum heads

 

Well, seems like at some point the heads will be off, that being necessary to change them; at that point, measure it, and then pick a gasket accordingly.

Or, as spitot suggested, have an array of them on hand.

I STRONGLY suggest not trying to eeek out every last tenth of a point by using a thin gasket. That's usually the road to disappointment; in particular, blown head gaskets.

 

thanks spitotrs305 that make some good sence. i just dont want to start the swap and be like **** I have to wait now to get a head gasket....

sofakingdom- yeh i dont wana go down that road of disaster.

would it be smarter to pull the engine out to do a head cam intake swap?

 

That kind of depends on what tools and facilities you have access to.

IMO it's a ROYAL PAIN to do a H/C swap while the motor is in one of these cars, because you end up spending about a day and a half bending over working on something a foot off the ground and 3 feet away from you. You won't be able to stand up straight again for about a week. I'd rather pull the motor. Plus, it's VASTLY easier to get things to go back together clean and right and leak-free, with it all out there in the open. But, I've done it the other way too. In one of these, you'll have to pull the radiator, A/C condenser, and the vertical bracket below the hood latch (or at least bend the crap out of it).

So, if you have a place and eqpt to pull the motor, I'd say that's easier. But if you don't, you can do it in the chassis, it's just less fun.

Take it to the quarter car wash first, stop off and buy a couple of cans of engine degreaser, and sterilize it, before you work on it. That's another thing that helps out the "fun factor", is not getting bathed in 100,000-mile-old schmutz on everything you touch. Whichever way you do it.

 

i would be doing it in my driveway might be able to get a place with a hoist. and some more tools. so you say spray the engine down with degresser? once its out or in? but if its smarter to pull it i might

 

Stock L98s from 1987 had dished pistons with approximately 12cc of dish/valve reliefs. You ain't gonna head gasket your way up into the 10:1 compression range. Mid 9s is as good as it gets even with thin steel shim head gaskets (.018"). Or you can mill your brand new heads down to ~58cc with those steel shims and hit about 10:1.

Really, what you want is a set of flattops pistons in that motor. Then you can hit the 10:1 range much easier with a properly chosen head gasket and un-milled ~64cc heads.

 

damon-guess soo, i just want trying to tear my whole motor apart,but if i gotta i gotta