In anticipation of these manifolds becoming scarece I have been gathering these manifolds and now have a pretty good supply. Most I've aquired have come from Chevy/Furd swaps. The last manifold I saw at a Mopar swap was $250. The D4Bs with the Chrysler part number are now allowed in Stock Eliminator which makes them sought after. I have D4B's on all the 273s I have both in cars and on engine stands.