1976 F350 clutch issue

[phillyshriv]

I have owned my 1976 F350 stake body truck [390 v8/4 speed/2 wd] from manufacture. The original clutch held up for many years, but eventually my guys beat it enough and I had to replace it.
Since replacing the original [years ago] ,I have put in maybe 4 or more clutches over the years. The 1st replacement and all subsequent clutches have introduced a shake, that was never there with the original, as you ease the clutch out when starting in 2nd. 2nd is the "normal" pulling-out gear, unless you are loaded..... then you need the crawler gear - 1st.
I have had numerous mechanics try to fix this problem - no luck. Big shops, small shops.....Yeah, heavier duty clutches, throw-out bearings. pressure plate. No luck.
I still have to start in 1st - which is a pain in the butt. If I am facing downhill, I can start in 2nd.
When you pull the clutch - you can see the scoring that is going on. No one has an answer.
Any ideas?
Thanks.
Shriv

[ToughOldFord]

I'd look real close at the pilot bushing/bearing then the bearing on input shaft on the transmission.

FWIW the original clutch would have had asbestos in it and would out last anything made afterwards. Anything that works well is outlawed.