1972 L48 valve cover bolt head markings

[Brian V.]

Hi all,
I just replaced my valve cover gaskets (350/200, 4-speed). From what I can tell, they were the original gaskets, and judging by the paint voids left by the securing hardware, the valve covers were never removed before.
The valve cover bolts appear to be original and all have a "D" head mark on them. Has anyone seen this before? I've read of "M" or "R" or even anchor markings, but never "D".
I'm a newbie, so any info is appreciated.

Thanks!

[Edward J.]

Re: 1972 L48 valve cover bolt head markings

Brian, my 72 L48 has NAT headmarks, my under standing is that more than one manufacture supplied bolts to Gm. D sounds like one of them.

[Joe L.]

Re: 1972 L48 valve cover bolt head markings

Hi all,
I just replaced my valve cover gaskets (350/200, 4-speed). From what I can tell, they were the original gaskets, and judging by the paint voids left by the securing hardware, the valve covers were never removed before.
The valve cover bolts appear to be original and all have a "D" head mark on them. Has anyone seen this before? I've read of "M" or "R" or even anchor markings, but never "D".
I'm a newbie, so any info is appreciated.

Thanks!

Brian------


The "D" headmarking is common on 1969 and early 70's small block steel valve covers. My 1969 had them. I've seen many others in that period, both Corvette and small blocks installed in other Chevrolet vehicles.

[Brian V.]

Re: 1972 L48 valve cover bolt head markings

Thank you for the info!
It's always nice to find out something is original, no matter how small it is.

[David K.]

Re: 1972 L48 valve cover bolt head markings

Brian, Do you have the latest edition of the 70-72 TIMJG?
Alot of good reading in that Judging guide.

[Brian V.]

Re: 1972 L48 valve cover bolt head markings

Thanks. I will have to order one of those. It will probably answer a lot of my silly questions.