You just gonna run it as-is or fiddle with it? It's probably all the torque your drive train wants to hear about, but what fun is it if you never break a u-joint or shear an axle?
Since it shows '86, non-cat, heavy duty, California, it is probably out of an F350. I say that because afaik, '86 is mighty late to be non-cat in CA, and the heavier vehicles were the holdouts for non-cat.
Why does that matter? As NumberDummy might say, you might run into one or more dumcluck parts people who just have to have the year/make/model to look anything up. They'll give you 1968 Lincoln parts if you just say "460".
I think you are correct for "custom" shafts, as it is doubtful any existing Ford shaft would work with that transplant. People try to match them up, but spending years going from one scrap yard to another would tire me out.
Your u-joints will be identifiable, and that should be the only concern. But if you do whack one, expect $200 give or take for a retube.