462624 Cylinder Heads-Good or Bad?

97350

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I just picked up a used 350 with these heads on them.I've read that they can be both good and bad depending on the year they were made.Is there a chart out there that lists all the block and cylinder head numbers that I can use to decipher what part I have?I was hoping this forum would have one.
 

ChevyHiPro

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Well, there's good news and a little bad news about these heads!
:eek:
The Good News; Chevy used these heads from 1976 to 1987 on 350 cid engines.
They were fitted with either 1.94" Intake/1.50" Exhaust, or 2.02" Intake/1.60" Exhaust Valves, all these heads had 76cc combustion chambers.
:D
The Bad News; these heads are crack prone!
:roll:
So, before sink a bunch of $$$'s into them for fancy machine work and expensive parts, ect., it would be best to have them magnifluxed to check for cracks.
:cool:
Are they good or bad? Depends on the heads actual condition and your plans for them.
Could be either way.
As for as making power, yep!
They'll do that, depending on condition.
Good valve size, nice combustion chamber size depending on the pistons used with them.
If there are no cracks, build'em and run'em.
If they have cracks, swap'em out for a better set of heads.

Hope this helps!
 

97350

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Thanks for the info.Is there a way to tell what size the valves are without pulling the heads?
 

ChevyHiPro

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Well, not really!
I mean the difference between the intake valve diameters is 0.008", the exhaust is 0.010"!
:eek:
So, it's basically, academic, for most purposes.

If you had the heads off to have a valve job done or whatever, then it would be important to know, but then, you could simply measure them!
Treat them like a first date, just enjoy them, she don't really need to know how big your valve is, to enjoy being with you!!
:lol:
 

OldschoolSteve

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I had a set on a stock 1978 350, prone to cracking from exhaust seat area into water jacket, mine did just that, on drivers side, # 3 and # 5 cyl but it had 156,000 miles on them. I also put about 4000 miles on the truck before I pulled it down. after killing the engine if either of those two pistons were very far down in the cylinder and it sat long enough, antifreeze would work it's way in. Killed a lot of skeeters when I fired it up though!
 

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