1975 Blazer!!!!

[mercado1211]

Hey Vile,

I was about to take the intake off after draining coolant to change the lifters and I thought I’d run it without valve covers. The valve covers had heavy wear marks from contact with the rockers. The knock disappeared. Lesson learned after a tear down and rebuild, always look for the simplest explanation for things.


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[mercado1211]

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[mercado1211]

The tear down was actually a good thing though, It had a Cam that wasn’t jiving with the set up. I couldn’t identify anything about the cam the original builder put in. He quit answering his phone. Two (5,7) cylinders were shadowing and the machine shop said it was a timing degree issue. The unknown cam had -3 etched on it so I might guess it had some custom grind.


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[VileZambonie]

Well I'm happy to hear you found the problem! Are they stock rockers or roller rockers? Some tall valve covers should remedy that pretty easily for you.

[mercado1211]

Thanks, I’m happy that ordeal is over as well. They’re stock stamped rockers. I have the tall covers but they hit on the sides of the rocker, the pushrod side. It has aluminum aftermarket heads with a configuration both style center bolt  and older valve covers. I’m going to try grinding some clearance with a. Die grinder today and see if it helps.


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[VileZambonie]

Good luck!

[mercado1211]

Thanks!


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[Shifty]

Would either the thicker Fel-Pro valve cover gaskets (VS12869AC- 7/32" thick vs the OE 5/32", the Permadry version, or even the performance 1604's that are 5/16" give you the clearance without grinding?)

[mercado1211]

I think I’m going to go and pick up some steel valve covers. The aluminum ones might still not give enough clearance if I grind them.

The issue I was having was the rockers were rubbing on the sides of the valve covers (pushrod side)pretty hard. I grinder one and decided not to even mess with the other one. I think these proform covers aren’t meant for steel stamped rockers.


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[mercado1211]

Hey Shifty,

I used some stock vortec style valve covers and it fixed. Runs nice and smooth no rockers bashing and knocking. Motors dirty cause I was running it with no valve covers and put a cardboard dam on after the fact.

Thanks for the input


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[mercado1211]

Sorry about hijacking your post Vile. I’ll go back to my mine now.


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[VileZambonie]

No worries. Got the carpet in, just need to set it outside in the sun for a bit.

[mercado1211]

That’s the next project for my sons K5. Looking good.


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[JohnnyPopper]

Sweet! Stock color?

[VileZambonie]

Yes, keeping all the factory colors. Saddle