Any of you have an original bore with pistons 283 or perhaps a 265 with the head off? If so, can you measure how far down in the bore the flat top piston is at TDC?
It's been asked here before.... a quick search is all it takes. https://www.jalopyjournal.com/forum/threads/283-piston-height-and-305-head-qun.197877/
When the shim gaskets were the norm the probably needed to be in the hole. Today with .042” gaskets I would cut the block for them to be flat after a preliminary ***embly measurement.
^^^^^But, unless there's a FelPro gasket out there that I'm not aware of the embossed steel gaskets that are .015" or .017" have a bore diameter of 4.100. In my case, I didn't want that weird little slit going back almost 3/16" from the edge of the bore to the inner diameter of the head gasket. I'm currently building a 305 and did a LOT of searching for a smaller bore, embossed steel gasket and never found anything. I was wanting to preserve all of the compression I could, so to stay with a "better fitting" head gasket I'm re-using the original steel gaskets with 2 coats of Permatex Copper Coat on both sides. Many references I found through searching say that has and will work OK. BTW....I realize all of this is quite a bit of thread drift from the original question, but it might still play into the picture. Lynn
You’re right,,,,the bore opening is 4.100,,,,,,but what is a normal opening on a regular blue Fel pro . Just about identical . Anyway,,,,,it’s hard to find parts like that for a 283 ,,,LoL . Tommy
Probably real spendy, however you might want to contact Cometic and see what they can do for you. A number of years ago they made me a set for a 4.125 bore aluminum sbc that were .090 thick, to lower the compression. Sort of worked. They sealed fine, but no squish didn't help and the roller cam was intended for 14 to 1 in a sprint car. We were just trying to get by for a couple events before lowering the compression and changing cams during the next rebuild. But the gaskets were great
When the 307 small block came out in '68 <all with 2 barrels>through about '71 they were small on the inside. My racing buddy in Houston would look for used 283-307 steel head gaskets for his S/S 55 Chev. NHRA race car. A '57 Chev. 265 has a thicker wall and will safely bore .125 to 283.<Good luck on that>283 blocks aren't that hard to find but shipping will kill them.
How about the early Caddy and Olds engines, they were the first m*** produced wedge heads. Did the have the .045 squish like the SBC?
Shouldn't you just calculate what it's supposed to be, and then measure what your block height actually is? What someone elses engine is may not be relevant to yours as they may have pistons from different manufacturers and blocks not only may have been milled before, but if original, they may not be parallel to the crank. If I remember correctly , deck height is 9.025 per drawing but you have to measure the block you have.
I get ya if trying to squeeze the engine for all it’s got, but in latter years when the 305 and 350 GM used in the F-bodies, the same head gasket was used for both engines. I recall this from the 3rd Gen page I used to frequent when guys tore their engines apart.
If you know stroke, rod length, and compression height, and deck height (per drawing) it should be easy to calculate what they were shooting for. Then throw in the gasket thickness. Actual measurements will vary somewhat. Remember also that leaded gas was plentiful when they designed the engine. I think Rod Length is 5.703 and compression height is 1.800 ,3.0 stroke and 9.025 deck. Don't know gasket thickness.
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