I have a "cat" pump that looks like the "source" pump in the middle of the last pic. Ain't used it yet (upcoming 451). I believe an 8 blade w anticav plate/smallest WP pulley you can find/reducing the vane to housing clearance to ~.040" for a more efficient pump. Biggest area 3 or 4 core rad you can fit/hi flow stat/shroud/thermal clutch fan 1/2-2/3 deep into it. fastest water speed you can muster. Bare block? drill a 1/2" water passage at the outside edge of cyls 3/5 and 4/6 & a matching hole in the head (punch a hole in the head gasket do not drill it/plug large coolant hole in the rear of each deck w a freeze plug and drill a 1/8" hole at the top (inside edge) of each of the (2) freeze plugs as the deck will b at a 45 angle to let air out at the top of each freeze plug.