and Nascar really is a completely different ball game. they run 358 CID's BTW, the block they run can only be a dry sump.....there isn't a single oil drain back hole in the whole motor, just fittings in certain places, and the outside of the block looks completely different. Where the water jackets are around the cylinders, the block pokes out I'm assuming for more coolant capacity, and their cranks are all REALLY smooth, everything is radiused, no square edges on the whole thing, everything is rounded off. The edges of the counterweights are a smooth radius. the stuff they run is really amazing, but I would NEVER buy a used Nascar piece.........they replace all their parts before they break, now whether they are going to break the next time they turn the car on, or 2 races later, they can't afford for a motor to die at a race. but those parts are BADLY abused.....8K RPM for 500 miles w/o breaks....those motors are designed to ONLY last as long as the race and no longer, so they can run the lightest and most on the ragged edge stuff.