I’m building a 392 Chrysler hemi for another project and using 6.86” big block Chevy rods . The early hemi rod journal diameter is very similar to stovebolt and GMCs at around 2.3125. Plenty of meat to offset grind to the 2.2 bbc size. It’s commonly used for ford and Chrysler stroker motors and bbc h beam rods are very affordable nowadays and available in several different lengths, one being 7.1” which would work well in stovebolt or jimmy 6. Might even adapt pistons from a small block Chevy,
