If you watch the meets, the List, The Bay, ect you can find(maybe) alloy heads, split ex mans & multi carb set ups.
check out http//rustyhope,com and then see member moose__ and his website There are several mopar threads here and a Plymouth social group Also milling the head is an inexpensive way to boost the cr and build some power. visit P15-D24.com for lots of flathead stuff and check moparsled's posts here. search flathead 6 and also search for post by Decostreamline
try to look at edgerton's page, they also do alu heads! www.edgyspeedshop.com you can also look at www.p15-d24.com it's a forum where this engine is the main character! you can find a lot of info there on hop up parts!
sorry for the double post about p15-d24! you can also look at http://www.stoveboltengineco.com/ for cast iron split headers and for an HEI
Thanks, guys. Trying to gather some info. I'm a long-time Mopar fan, but have little experience with flatheads. I appreciate the help!