413 Motorhome parts worth anything to anyone??

I have a 413 and 727 from a 1972 motorhome I'm tearing down and was curious if there was a market for the heads, manifolds, and other hard parts for these engines? I was planning on just tearing down and keeping the block, crank, rods and pistons and rat-hole-ing for a rainy day. Wanted to put this in general discussion prior to opening a classified ad because I didn't want to waste time if there wasn't any interest. I'm not really familiar with the motors.