[Greek64GTO]

I've just about got the numbers matching 1964 389 torn down and I am making my list of imrovements and parts needed.
I did a search of cylinder head bolts and their markings. I ran across somewhere BearGFR was talking about letters and markings on the pan bolts and a few other areas.

I can't find in my search within this forum or on the internet the actual correct markings on the cylinder head bolts.
Much good info on stock vs ARP and longer than necessary bolts, etc. Great forum this place is.

Here is a picture of a sample of my headbolts. I have the circle on bolt head. I also have Rockford grade 8 markings.
Naturally I also have the stud on top of head bolt (not pictured).

Can someone chime in and tell me what is correct for head bolt markings? I want to keep this engine as original as I possibly can.

Thanks

Tom

 

[BLK69JUDGE]

From the few dozen 67-70 Pontiac engines I have pulled apart I have never seen a factory engine use ALL the same foundry marks on All the engine head bolts .. changing between length s. seems different foundries marks we’re used on same engine

 

[1971LemansWisc]

Tom - Agree with BLK69JUDGE - below are the Head Bolt Markings on my '71 WK 400.

I think they used whatever was in the appropriate Type/Length Head Bolt Bin at the Engine Assembly Plant at the time.

I have the bolt on Oil Drippers - hence the 4 studs inside the Heads.

Left Bank Facing Engine – Front to back Outside Head
Concentric Circle (Same as the Bolt you have.)
1047 CP
Stud
TR (Have the 6 radial lines signifying Grade 8)
TR
Left Bank Facing Engine – Front to back Inside Head
TR
Stud
Concentric Circle
Stud
1047 CP
Right Bank Facing Engine – Front to back Inside Head
TR
Stud
Concentric Circle
Stud
TR
Right Bank Facing Engine – Front to back Outside Head
Stud
Stud
Concentric Circle
Stud
Concentric Circle

Hope this helps some.

 

[lust4speed]

Same thing, haven't found an engine that had all the same bolt head markings.