forget the R, a 283 will have 165-195 bhp without the loss in power from the differential, trans, alternator, water pump, and things like power steering pump, muffled exhaust system, etc .... the currently used SAE net hp takes account of the accessories, but not the driveline - you can find lots of 300hp small block variations, once you figure out how to get whatever you can afford up front, then worry about finding a dyno to see what you're getting to the ground
try some "how to" books about small or big block Chevies, the old HP Books by Dave Vizard are good if you can find them
Bill
