71 Big Block Valve cover bolts

[Lyndon S.]

What is the consensus on head markings on 71 valve cover bolts for big block cars. Is it that a bolt with a D is wrong? Yet I have seen numerous low mile cars with some of those D valve cover bolts. Are those not acceptable as OEM ? I know some of the catalogs only list the TRW as being correct, or I should say the only ones they sell.

[Rich P.]

Re: 71 Big Block Valve cover bolts

D is correct for 70-up big blocks.

Rich

[Lyndon S.]

Re: 71 Big Block Valve cover bolts

I thought so, I had seen to many examples of it on low mileage cars. But seem to remember being told they were not correct.
Does anyone reproduce that D bolt, that you know of?