Does anybody know the production run numbers for the Astron motor heads (I'm talking about M1, M2, etc.)? I'm trying to source where, and when a M3 head came from, for engineering purposes.

i don't know the casting series numbers for certain but a M3 is deffinately pre TR and probably pre TP

when we pulled the head of my aunties TN elite - it was a M3

Dunno if that is the original head

Hi, I have a M6 head came from a TS

Yeah. Reason I asked was the head of this carby car is M3, my original motor was also M3, though my replacement head was M4. (Replacement was from a TN carby)

haVE A M3 HEAD ON MY FLOOR, ITS OFF A TP CARBY...STUPID CAps

Hi, I have a M6 head came from a TS

all the TS with EFI i have seen have had a "M9" head with heart shaped combustion chambers, I have three TR engines here and they have M7 heads on them, i have seen M6 on TR's before.
Did you have the M6 head off your TS?
Did it have round or heart shaped combustion chambers?