i know they did a 32 valve conversion on the old big block still using the stock camshaft and pushrods and some realy trick rockers
arias made a set of billet 32 valve heads for the small block too
both where somwhere in the eighties
it turned out you can actually get better flowing heads with two valves per cilinder and some extensive development work wish is the reason the LS engines still have 2 valves per cilinder
maibe this will help :
http://www.69pace.com/6shooters.htm
theres one that made an aluminium inline 6 head by lopping of one combustion chamber of a set of good flowing aluminium v8 heads and weld them together