Cracked Head......?
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 990
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From: North Texas
Cracked Head......?
Well, I pulled off the sheild by the #5 and #7 cylinder and what I thought was a blown head gasket looks like a cracked head. How common is this on factory cast heads (1970)? :confused: It's right along the casting line.
Good news is no water in the oil and no oil in the water.
I'm not really sure what to do at this point. I can't seem to get any history on the engine (Matching numbers block with 122,xxx mi) but it looks like it's been out at some point. My issue is with the oil pressure - 35psi..is all I ever get on the factory gauge and I don't see any leaks so sould I believe it?
I guess I have a couple of options: new heads or a new engine. If I pull the block, I'd probably put itt in the corner of the garage until winter then re-build at my leasiure.
Thoughts? :(
Good news is no water in the oil and no oil in the water.
I'm not really sure what to do at this point. I can't seem to get any history on the engine (Matching numbers block with 122,xxx mi) but it looks like it's been out at some point. My issue is with the oil pressure - 35psi..is all I ever get on the factory gauge and I don't see any leaks so sould I believe it?
I guess I have a couple of options: new heads or a new engine. If I pull the block, I'd probably put itt in the corner of the garage until winter then re-build at my leasiure.
Thoughts? :(
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Re: Cracked Head......? (1970-Bronze)
Heads are easy to replace compared to pulling the engine or even a cam change. :yesnod:
The bottom end is good for nearly 350k mi but the cam lobes start to wear and power starts to decrease at 135k. It will still run fine just a little less power as time goes by. And to replace the cam it can get ugly real fast on a shark. First remove and replace the carb & intake, then R&R the radiator (may need new core and all new shroud seals), water pump, oil pan needs to come off to remove timing cover & gears, cross steering arm and starter need to come off to remove oil pan. Not just a weekend job when you find all the Bubba fixes along the way.
For just some used heads I like Performance Heads also called Performance Chevy Products (602) 254-9586 out of Phenoix, AZ. They sell pocket ported used heads with new valves for cheap($500-$600). And this would be fine until you want to change cam (or rebuild block). Now everyone wants to rebuild the whole block when just a new cam and seals with a valve job is good for another 150k mi.
Now this is really up to you and what you think you can handle. Rough labor estimate for just R&R heads and cam would be $1200 - no parts. :seeya
Good luck. cardo0
The bottom end is good for nearly 350k mi but the cam lobes start to wear and power starts to decrease at 135k. It will still run fine just a little less power as time goes by. And to replace the cam it can get ugly real fast on a shark. First remove and replace the carb & intake, then R&R the radiator (may need new core and all new shroud seals), water pump, oil pan needs to come off to remove timing cover & gears, cross steering arm and starter need to come off to remove oil pan. Not just a weekend job when you find all the Bubba fixes along the way.
For just some used heads I like Performance Heads also called Performance Chevy Products (602) 254-9586 out of Phenoix, AZ. They sell pocket ported used heads with new valves for cheap($500-$600). And this would be fine until you want to change cam (or rebuild block). Now everyone wants to rebuild the whole block when just a new cam and seals with a valve job is good for another 150k mi.
Now this is really up to you and what you think you can handle. Rough labor estimate for just R&R heads and cam would be $1200 - no parts. :seeya
Good luck. cardo0
