Head Bolt head stamp ID

[440ehigh]

I'm looking for more information on the type of head bolts head stamp I have on my motor. It seems most big block motors head bolts had the H head stamp bolts. See attached picture of the head stamp of the ones on my motor. Does anyone else with original fasteners on there motors have head bolts that look like these. There's someone selling some head bolts like mine on eBay and states that these type of bolts were used on crate motors assemble in Canada. Anyone know if that is accurate or more information on that.

[Headjam]

1970 383 HP

Original head bolts. "H" style.

[440ehigh]

Ok thanks it seems most are the H style and that's the only style the MMC book calls out for head bolts on big blocks. But as with anything with these cars there's always different variables. Trying to see if anyone has bolts like mine.

When was your motor assembled?. My engine has an assembly date of 1-13-70.

[Headjam]

How do you know the assembly date for your engine?

My cylinder block was cast 4/17/1970 and my Challenger's SPD is 508. Engine would have to been assembled between those two close dates.