1956 cylinderhead 365 cui

[CadillacSDV56]

Hello,

I hope somebody can help me. My cylinder head on the driver's side is cracked. Good cylinderheads are rare to find. My question is now, also fit cylinder heads from 1957,1958 or from the 390 cui block? The cylinderhead gaskets till 63 are the same I think.

Happy easter time to everbody.

[fishnjim]

According to the parts list, there's an "early"(by motor numbers) '57 that probably drops in.   The later use different pushrods, so you have some "adapting" to do to make them work; length, lift, etc.   Lifters appear the same.   The blocks are all similar til '61, just the stuff that goes in/on changes but moving parts have to be done correctly to tolerance. 
I'd pursue having it repaired first or find a drop in replacement.  That will give best car value. 
If your head can not be repaired, and you absolutely can't find one, then you might want to go through the hassle/cost.  The later ones also cracked, so finding good ones is key, ie not gaining much.   I'd change both sides if I changed to non - '56-57 head years.  And old heads need new valve seats and valves for today's gas.   Once you're that far in, you need to consider what else needs replaced/rebuilt.   You might have more cracks that you don't even know you have.   They're a bit notorious for cracking.
Maybe someone will step up that has a good set...Post on "want to buy" forum.

[LV 57 SEDAN DE VILLE]

On my 57 I used 1959 390 heads. You need the rocker shaft assemblies from the 390. The stands are different the center the rockers on the larger valves. Use the pushrods from the 56.

[CadillacRob]

Fwiw, my machine shop repaired my 365 heads.  Both cracked.  Old machine shop guy said he wasn't surprised at all, said they all commonly cracked back then.  He pinned them - not sure if that's the correct terminology.  Basically you drill a hole on either side of the crack, tap a hole, screw in a plug, drill and tap another hole over half the previous plug, and you continue, overlapping each previous plug until it is covered.  Then remachine.

[gary griffin]

The taps and pins method is called stitching and can be done by most component machinists!

[CadillacSDV56]

Does anyone knows the cast number of 1959 or 1960 390 lh and rh cylinderheads?

[J. Gomez]

Does anyone knows the cast number of 1959 or 1960 390 lh and rh cylinderheads?

FYI

https://www.jalopyjournal.com/forum/threads/caddy-engine-casting-numbers.397279/

Good luck..!

[chstitans42]

T Jager,
i am parting out a 56 Fleetwood, and have a set of cylinder heads I would be willing to sell you. I can send you pics of what ever side you want, seeing they are already pulled from the car. Can you be more specific where they crack? Id like $100 each. Let me know if you are interested.

[CadillacSDV56]

Thank you for the helpful answers.

T Jager,
i am parting out a 56 Fleetwood, and have a set of cylinder heads I would be willing to sell you. I can send you pics of what ever side you want, seeing they are already pulled from the car. Can you be more specific where they crack? Id like $100 each. Let me know if you are interested.

I need the left cylinderhead, the crack is at the intake valve and through the seat.