I would first remove the valve cover and see how the rockers, cam, and rocker shafts look. If they look clean and unworn, I'd bolt a starter to the engine and run a compression check. If the compression is good, I'd just bolt the motor in and see how it runs. I think I'd also take the float bowls off the carbs and make sure there's no crud in there before attempting to start the engine. Let us know how it turns out. Colin