Valve Cover Bolts Headmark

[Bill #34162]

Can someone tell me the correct valve cover bolt head mark or marks for a 70 L46? Thanks.

[Joe L.]

Re: Valve Cover Bolts Headmark

Bill-----

I don't think that there was JUST ONE headmark used for these bolts. I believe that one correct bolt is an indented hex head with an "M". These were used on engines with aluminum valve covers.

For small blocks with steel valve covers of the 69-70 period some folks say that the "TR" headmark bolt is "correct" and it may well be ONE of several used. However, most of the original 69-70 engines with steel valve covers that I've observed (including many apparently unmolested examples seen in self-serve type wrecking yards) have a large "D" on the head of the non-indented hex head bolts.

[Dennis D.]

Re: Valve Cover Bolts Headmark

Have the indented head with the "M" on my 70 L-46

[Dale Pearman]

Fastener Industry

nomenclature is "cap screw" for a bolt without nut and "untrimmed head" for the dished, indented, recessed head. You have an untrimmed cap screw.

Dale.

[Dale Pearman]

Re: Valve Cover Bolts Headmark

An untrimmed cap screw from Michigan Fastener Products. Several manufacturers supplied the fasteners for Corvettes at any one time. GM had an acceptance procedure for all fasteners. Different fasteners from different manufacturers had different head markings BUT they all had to pass quality testing.

Dale.

[Bill #34162]

Re: Thanks All *NM*