[74chevyflat]

IS this the original steel shim gasket? what is the thickness? anyone know?
I have searched for this part number and i cant find anything. Its for my engine just need to know if its worth buying them. the $40 lot is for 4 steel gaskets clearly i can see they are shim gaskets from the picture.

[matt167]

C3 is 1963 and they didn't make a 200 in 1963.. 1963 would be a 144 or 170 CI and a bore too small.. steel shim gaskets have been discontinued since the 80's, but in any case, they are .025 compressed... just get a Fel-pro and have the head milled .025.. the fel-pro composite gaskets are .045

[74chevyflat]

how can i tell if my head has been shaved before or not?

[74chevyflat]

all of the parts for a 3.3 say 63-80.

[cobalt327]

Your engine has seven mains, right? Because if you have a 4-main engine (early '64 200 cid), it's not what you want for hotrodding, IMHO.

[cobalt327]

From HERE:

C9DZ 6051A- '65-'69 GASKET CLY. HEAD 170-200. Looks like the gasket's bore diameter is large enough for the 200.

There are numerous "C3xx" p/n's from '63 to '68.

[matt167]

Originally Posted by 74chevyflat

how can i tell if my head has been shaved before or not?

correct way is to cc the chambers. IIRC, a E0 ( 1980 ) head should be 57cc stock, so if it's less than 57cc it's probably milled, but if it had a shim gasket, then chances are it's not been milled... cut it anyway tho. it's only going to give more compression and the cylinder head can get cut .090 w/o sonic testing

[74chevyflat]

up to .090???????????? anyone concur? is this a good way to bump my compression to use a cam?

[74chevyflat]

hey cobalt thats where i found the info for the gaskets at.

[74chevyflat]

someone had already been into the engine before bc it didnt have the stock shim gasket and the #1 piston was missing half of a compression ring. the gaskets were all NON stock materials, and the cam i measured has a .240 lobe lift.

[74chevyflat]

will the Steel shim gasket have better sealing properties then an aftermarket say Felpro? laminated steel?

[matt167]

composite gaskets keep seal longer... IIRC, it's about 2cc per .010" of thickness removed. so you could kind of calculate your compression ratio. but don't just cutting off .090" just because you can.. if you figure, your engine has 8:1 with 57cc chambers, and the older engines had 52cc with 9.2:1. so if you shaved .075 off, you will achieve 9.2:1 with stock pistons

[74chevyflat]

the heads have a 59 cc chamber after deshrouding. now i know they have been milled bc i can see the score marks, but how to i measure to find out how much they have already been cut? isnt there like a peg on the end of the head somewhere like the SBC.??

[cobalt327]

Originally Posted by 74chevyflat

will the Steel shim gasket have better sealing properties then an aftermarket say Felpro? laminated steel?

Steel shim head gaskets are more sensitive to the deck finish as well as the flatness. A shim gasket will work fine and seal for the life of the engine, provided the decks are prepared correctly.

If the decks aren't fresh and/or flat on the head and block is where you can run into problems using shim head gaskets.

[matt167]

theres no peg that I remember on any of the heads.. you could cc the chambers and see where you end up. if it's 2cc per .010 removed, then if you come up with 55cc or so, then you know that it has been milled approx .025