I don't know how often he likes to do it, but call Piers. A TDR member from my area who has a 92 or 93 3500 dually bought a fully reconditioned 98 12 valve engine from Piers late last year.
If you were at May Madness earlier this month, he had the truck there, and he told me the TDR admin folks were all over it with their cameras taking pictures for a possible future TDR magazine article.
I am refering to "drives mopars".
Tom