2 weeks ago I saw a Dodge 3500 with a V10 at one of the salvage yards. The truck had been rolled. I spent 20 minutes looking at that engine, because back when I ported heads for a living, I did a pair of those heavy iron monsters.
It sure is tempting. It is heavier than a 454, but offers better low-end and better top-end, stock versus stock, at a similar price.
I'm trying to scrape together the $250 I'd need to get it if it's still there. It had an automatic and a transfer case, while I'd convert it to a T56.
Last year I saw a Ford E350 with a Triton V-10, but aside from the difficulty of pulling a V10 from a van, it was hydro-locked, as is so typical of Ford modulars. It is lighter than the Dodge, mostly due to the aluminum heads, but only 425 or so cubic inches, well, I didn't want it. Even at $175. It would also take a T56, or a T45, or a TR3650, or a TKO.
COMP does cams for the Dodge Ram V-10, IDK about the Ford V10.