Correct Head Bolts for a 66 427-425

[Craig S.]

I need a correct set of head bolts for my engine when I begin assembly...since I bought the block and heads separately, I have none. While I am a huge fan of ARP fasteners, and intend to use them for all the internal bolts, they would not look at all correct for the exposed head bolts, and some can be seen through the oil filler hole I believe. I remember there was a discussion on this a while back, and I believe Joe indicated that the big block bolts were still available from GM, but I don't recall if the head patterns were still the same as the originals. Help from anyone is appreciated, and, if I can find the correct part numbers of the GM bolts that would be helpful too...thx!....Craig

[Joe L.]

Re: Correct Head Bolts for a 66 427-425

Craig-----

Big block head bolts are available from GM under the original part numbers. However, the headmarking has changed. The originals and current ones both have a "cross" headmarking, but the "cross" is different. On the originals, the "cross" was large, extending all the way to the perimeter of the head. Also, there was an "m" in one corner of the cross indicating the manufacturer, Michigan Screw Products. On the current bolts, even though the part numbers are unchanged, the "cross" does not extend all the way to the perimeter of the head and is very noticably different than the originals. Also, there is an "o" headmarking in one corner.

I believe that Paragon sells reproduction head bolts of the original configuration.

[Craig S.]

Re: Correct Head Bolts for a 66 427-425

Thanks Joe! As always, your input is very much appreciated!...Craig