Historic racing tyres L or M section

[carreraplanes]

Anybody know what's the difference in terms of historic racing eligibility between Dunlop L section and M section 204 compound tyres? I've got a stack of M section tyres with my pre 66 Imp but some of the events I could be entering specify L section. What's the thinking here

[carreraplanes]

Thanks Chevron. I'm doing HRDC. Several classes based on year. The requirements for tyres on the entry forms read different every time but run something like:

DUNLOP ‘M’ SECTION CR65 ‘204’ - FIA CARS ONLY (or ‘L’ SECTION)

Not sure what it means FIA cars only as you don't need papers to run just need to be in period spec or so it seems. Or perhaps FIA cars are defined as post 64 only for some reason?

Did have the tyres stacked in a dark corner of the garage. Will put them in council bin bags, thanks for the advice. I did buy a durometer and they all came up about the same. Is there a target reading I should be looking for on the 204 compound

[carreraplanes]

Thanks Chevron I'll contact Julius....