I saw an advertisement recently for 440source and figured that I would take a look at their web site. They certainly have lots of stuff exclusively for the B, RB and Hemi (second gen) engines.
Part of the reason that I posted this to the Imperial site is that they have rebuilt OEM dampers for under $100 and many other interesting items new and used/refurbished.
Of recent interest, they list all casting #s of used open chamber heads (906 through 452) at $99 each head and sets of the 915 heads at $350. Someone was asking recently about the value of the 915 heads.
If you need an engine or transmission related part, they may have it. It is fun browsing:
Fred Joslin