For sale is a set of AFR 185 #1492 Renegade heads that have 58cc combustion chambers. I had a machine shop convert them to 3/8” stud mount and bought new studs and guide plates.

They also have PAC 1206X valve springs for hydraulic roller cam. These were on top of my 331 with -5.200 cc flat top pistons and made 10:1 compression.