Anyone have a layman's explanation between the F-41 vs F-40 suspension packages? and is HD service the same thing? Clearly front larger and rear sway bar, 12 Bolt, springs based on equipment via. T-400 and C-60 A/C seems to be the biggy's, (the spring charts can be confusing) and I assume as Donny says the shocks would be made out of unubtainium (or out of my price range anyways, what would be a reasonable newer shock replacement?
HD, is that a taxi thing, something completely different, or added to F-40 F-41 as in HD radiator ? Any reasonable input is better than none. Assembly guide shows the 427 has a return fuel line, is that on all 427's or another mistake in the assembly guides, as there appears to be a few different assembly guides out there.

Thanks
Bill Hickle