cracked 273 heads

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TerraBella

TerraBella

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I got the bad news today, one of the heads on my 65 273 comando is cracked and not fixable.
So Im looking for ideas on what way to go.
should I look for another 65 273 head,knowing that a wrong size head gasket is all that is available, And that is what caused the problem in the first place. or go with the 304 heads if thay work on a 65?? 273 or put a 318 in it and call it good. or is that a can of worms too. like engine & trans mounts, trans out put shaft ect.. any help THANKS in Advance!!
it is in a 1965 Barracuda Auto trans
 
Not sure how a head gasket could cause a crack - unless it blew one. In which case the new gasket won't hurt another head. They are not too hard to find - find them local to you or replace with a set of 302 318 heads. Then you can run the later intakes too.
 
Per another members thread, the later heads conflict with the early a-body exhaust manifolds. Might have been left side only ( I forget ).
 
Yes if he uses the later "302" castings & stock manifolds the dr. side manifold will just bearly hit (@ the air injection port where the flat part of the exhaust manifold is) its an easy & quick fix though,just grind that spot down a little on the head (don't take much) & get the clearence neede & presto! Good to go!
 
Also, if he has a 1965 273 the bolt angle will be different on his intake, so if he moves to the "302" heads he will need to swap intakes too.
 
Yes it is a 65 273. so swap out intake and grind driver side head,( i think i looked at a thread on that) the "302" is that head only from the 85-86 years that work?
 
what caused the problem in the first place? other heads will work, one of the best heads is the 1988-91 318 swirl casting #302 head with around a 60 cc chamber. most other 318 heads are around 64 cc - compression lowering chamber, except the 1967 318 casting #2658920 with a 57 cc chamber. the 1965 intake can be ground or machined around the bolt holes to bolt onto later heads
 
Not so sure what caused the problem, my mechanic thinks in part too large of head gasket & a lean burning valve. I have found a set of heads in Detroit with a 4323302 # on them dose that sound like what i need?? Thanks for your input


OTE=Marcohotrod;1970809940]what caused the problem in the first place? other heads will work, one of the best heads is the 1988-91 318 swirl casting #302 head with around a 60 cc chamber. most other 318 heads are around 64 cc - compression lowering chamber, except the 1967 318 casting #2658920 with a 57 cc chamber. the 1965 intake can be ground or machined around the bolt holes to bolt onto later heads[/QUOTE]
 
The head gasket leaves a lot of dead space, but if the gasket is sealing there should be no problem. Do you have a picture of the gasket and the block's gasket surface where it blew?
The issue is the other 318s I think with the exception of some '68s have open chambers which will drop output further. Not tremedously, but drop it, plus they don't have the induction hardened exh seats. So I'd go 302s and get an intake for it. As said the manifolds will clear - after a little clearancing. I gotta beleive there's a 64 or 65 273 2bbl somewhere closer to you too. They're free or cheap usually for the whole engine.
 
As far as head gaskets are concerned, Cometics makes a 273 head gasket in different thicknesses. They aren't cheap though.
 
Yes there about 90 bucks each before taxes. The sealing ring is still @around 4.100 ish but the material extends to whatever dia you want.
 
I think i found a set of 302 heads near by. casting # 4323302 Do you guys know if that is the correct # I will try to post a photo or two of the gasket,and will be sure to investigate the valve issue,with the machanic who is helping me out. thanks for all of your input
 
Big Joe says the valve was burnt from the last engine rebuilder not getting all the Gunk out of the block and gunk in the cooling system not properly flushed out
so he thinks it was getting HOT. I'm going to get it all clean and flushed this time for sure.
 
Somebody correct me if Im wrong;
Cooling system temperature runs 160* to 195ish
Combustion chamber temp runs 1000* to 1400ish,maybe, on your 273,Full-load,WOT
Temperature to melt exhaust valve around 1800*
 
302 heads have a heart shaped chamber, cant miss it. go with a performer intake, itll bolt right onto a 302 head and has the small ports. 30 lbs lighter than the cast iron one too. if you want to go single plane like the original, an Edelbrock streetmaster 318 will have small ports.
 
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