Hi Dave,

Not sure what a 'L' head is?

But I have both a 'M' head and a 'M2' head and they are slightly different.
Very obvious on the outside with machining marks, and the ports are way better with the 'M2'.

I believe the original 'M head' is a copy of the first 1965 Alcoa head but that seems a bit 'far fetched' after 50+ years... spank

Carpe diem, quam minimum credula postero, thanx Horace!

There’s no point trying to fix stuff that ain’t broke,,, 'but if ain’t broke',,, you is not trying hard enough...