yeah, I mean so much loose property in there.... I ran 15.3's in the 1/4 with a stock 360 D150, 3.21 gears, single exhaust. It's so hard to compare unless all is equal.
i'm not gonna take the D300 to the strip, mainly because i'd have to remove the stakes and that's a gargantuan pain in the ***, and my back hurts just thinking about it.
but for all intensive porpoises, the trucks are fairly evenly matched in equipment with the big one getting deeper gears but washing that with the much taller tires.
having recently driven both, Lawrence Le Beouf straight steps all over the the fleetside everywhere it counts, at least for the type of driving/use i do or would need. and that's not trying to be a put down on mid 70's trucks which i love and are great, either. his 73 is a *much* more comfortable truck to drive and is clearly more mechanically refined. but in pure technical terms it is "dog **** slow".