Re: 65-6 327 ?'s
Check and replace what items are in the rotating assembly, if you want ARP bolts, go for it, change rods, if you want, if they have non-cast surface on the sides, then excellent stress-relieved GM rods, if there is a pink strip on them, you're lucky, GM's 'pink rods', clean everything, size in a set of bearings and chose the ring material, moly filled top ring is good, buy a fluid balancer, 6 inch would be fine, take along lightweight flywheel and pressure plate, and have the assembly balanced. Stock oil pump, widened sump oil pan.
The idea is reduced weight/mass to rev faster and balanced reducing the high rpm buzz.
Full tube equal length 1.62" headers, about 28-29 inches long, 3 inch collectors with extensions making the total length, from the merge to the end, about 15 inches long.
Buy a 5 inch alt pulley.
Give a man a rescued dog for the health of both their souls.
'With age comes wisdom, but then wisdom ages you even more.'Other Stuff' GO CUBS!