Im pretty sure the top mounts are in a different position too Jumbo 
the M model TM had a fair bit more rear travel than the L .
Its not that obvious unless you have a Std L model and a Std M model side by side .
But in saying that Im pretty sure every thing bolts across the models 
yeah there a minor tweak at the top frame mount that i can see Bill, but i doubt that would increase the length of travel to any significant amount. Majority travel diff appears to be on the swing arm mount where the shocks are moved forwards.
Re:The interchangeability between models - i'm think i've read here somewhere here from some TM experts that the pivot bolt is smaller on the 74 L models. not sure about the rear axle end either I suspect that the L model has a different chain adjuster set up on the brake plate side too that might affect the wheel clearances. 211 (Dave) said he knows what mods are req'd, but as yet hasn't elaborated
appreciate your input
