318 Connecting Rods and Crankshaft

way overthinking this
Scat 4" crank (no Eagle)
at your rpm the rod ratio makes no real difference
and besides you are still better than a 383 or 400 chevy with a 6" rod
pick a popular combination
if you have to use stock heads use the KB pistons
power Is in the heads but you do not have to go nuts with that combo
find ones that flow well at 300-400-500 lift
at that rpm short cam with lots of lift
sort of an "engine masters" build
long tube headers
dual plane manifold with q jet or AVSII
with your build cubic inches really matter