high water temp issues

There's.....lack of air flow, lack of water flow and undersized radiator. On those giant cubic inch small blocks, I have to wonder that the water jackets and cooling passages, as originally designed, are insufficient for that many cubes.

I'd go with a full-flow oil cooler system as well (with the cooler mounted somewhere OTHER than in front of the radiator!) I did it when I had a built 340 in my A-100 and it dropped a good 20-something degrees off the coolant temps.