I built a 408 primarily because the larger displacement kits put the wrist pins in the
oil ring lands and I was concerned about
oil consumption.....the Eagle 408 kit uses inserts to control
oil!!
The other thing we found is notching cylinder skirts on stock blocks to clear the crank weights and rods becomes more pronounced with higher displacement kits??
I have heard that the 393 kits are much simpler and make almost as much power as the 400+ kits!!
My $.02 FWIW!!
Coosawjack