1969 SB Harmonic Balancer Pulley Bolts

[Steve M.]

Doing a frame-off on a 1969 350/350 convertible. Between the motor rebuild and my shop I am missing the 3 bolts that attach the pulley to the harmonic balancer. I have looked on the Forum and can not find information on the finish of the bolts for a 1969. From some of the post it appears that earlier years were zinc/cad plated but nothing conclusive on the 1969. I already have several sets but need to know how to finish. Any help on finish and head marks will be appreciated. Thanks Steve

[Joe L.]

Re: 1969 SB Harmonic Balancer Pulley Bolts

Doing a frame-off on a 1969 350/350 convertible. Between the motor rebuild and my shop I am missing the 3 bolts that attach the pulley to the harmonic balancer. I have looked on the Forum and can not find information on the finish of the bolts for a 1969. From some of the post it appears that earlier years were zinc/cad plated but nothing conclusive on the 1969. I already have several sets but need to know how to finish. Any help on finish and head marks will be appreciated. Thanks Steve

Steve-----

The finish was phosphate. The bolts were 3/8-24 X 3/4" and GM 280M material grade (3 lines). I don't recall headmarking

[Steve M.]

Re: 1969 SB Harmonic Balancer Pulley Bolts

Thank you for the information. Steve

[Rich P.]

Re: 1969 SB Harmonic Balancer Pulley Bolts

Steve, here's some of your choices for original head markings. for 20170221_144616.jpg69 I would use Nat, as, ch or []. if you don't have any originals let me know as I have multiple sets of each 20170221_144616.jpgheadmarking.

[Steve M.]

Re: 1969 SB Harmonic Balancer Pulley Bolts

Thanks for the great input. I also have about 5 sets that I have collected, just need to pick the best one. Thanks Again Steve