I have original engines. Mostly 283s and a couple 350s that were pulled out of corvettes. I've matched the engine and that heads. And they match for the years I've looked up. I have the Corvette black book so I know heads and engine match. Im going to check the carb, distributor and alternator on them. One is a 70' 350 4 bolt. A 58' 283. 71' 350. And 60' 283. Again all the numbers match. I was just trying to see if anyone is interested.