I'm pulling the 383 out of my 70 RR and just had a quick look at the heads now that the valve covers are off.I've gone through all my info and can't nail down a few things.Maybe someone here knows more about these heads.Here's the numbers...

Driver's side-2843906-10 with 05050 both numbers cast on head

Passenger side-2843906-9 with 05070 cast on head

I'm sure they're 906s but what does the -9 and -10 mean?Passenger/Driver side?Then the 5 digit number has me completely stumped.The block is dated 9/17/68 2468130-12 (LL)...it's a very early production run 70 RR...

Any help would be greatly appreciated,thanks

Dave

The heads start with a -1 then each time the sand casting molds are changed after a period of time they go to -2 & so on. I do not know what the 5 digit # means but I've never heard of any mention made of that # & I dont think it has any bearing on application/specs/casting date etc but it certainly was put there for a reason & has to have has some meaning that it's referencing.

The 5 didit code is the date they were cast , one on 5/5/70 , the other 5/7/70

Guys thanks for your help...this site has been really great especially to a rookie like myself.Very much appreciated...

Dave