These regular cars have very little value, do an engine swap. You can keep the original motor under the bench, if you want. The 267 is a dog, my BIL had two 81's both with the 267, one for parts. His plan was to buy a 400 hp 350 from GM with warranty but he sold them both. Honestly since GM Canada bastardized these from the factory, get one from them with a warranty. Of course sbc cores sell for nothing now thanks to the LS, so you can find them all over the place.