In 1964 my buddy Mike V. bought a trashed-out '56 red Corvette. Old Corvettes were relatively cheap then, especially ones that had been rodded hard and not taken care of. But he had to have it and so he bought it. The old 283 lasted for awhile, but he decided to put 2-4bbls on it, and that really hastened it's demise! After the 283 blew the car sat at a friend's garage for months on end. Mike was looking for a 327, but since they had only been out about 2 years then, and he didn't have top dollar, he was having a hard time finding one. But the guy who ran the garage had a 426 Dodge Wedge-head from a wreck, and he convinced Mike to put it in the Corvette!~! Yup! A 426 Dodge Wedge in a '56 Corvette! This was done, although things were REALLY a tight fit. As I recall you had to lift the engine to change the spark plugs. But it flat out RAN!! We took it to Kansas City on a fun trip once. I borrowed it to go out with a K. C. girl and later that night stopped at a gas station to fill up--(Something you had to do a lot!) The car turned over a few times and then the battery was dead. So I just sat there and asked several knowledgable-looking guys who came in for gas if they had jumper cables. I found one who did have cables, and when I popped the hood on the Corvette he stared and stared and finally said, "What the hell kind of engine IS that?" I told him... his jaw about hit the ground! We didn't do any official drag racing, but it was one of the faster cars I've ever been in.
Oddly enough the other "fastest car" was my girlfriend's '59 Corvette which someone has stuffed a built 396 into. She bought it off of a car lot because she thought it looked "cute". She had no idea! And I didn't either until I drove it. That car was also very tough. This was in 1968 when you could still get old Corvettes relatively easily. The 396 sounded very smooth, whoever had built it had not put a race cam in it, but it was very, very tough. Very fast. It felt faster than Mike's 426 if truth be told. Someone with a tow truck stole that 'Vette from the side of her house in 1970. Never saw it again.
By the way, at that time I had a '58 'Vette with a 327 300 H. P. in it. T-10 4-speed (which I was afraid of shelling out) and both tops. Boy do I miss that car. That was the best travel car I ever drove--I could keep my legs completely streched out in front of me. It wasn't in the league of the other 2 'Vettes, but it had a lot of power. I was running a single Quadrajet on it and had several rear ends under it at one time or another. I hated the 4. 11 because I didn't like the high RPM's when on long trips. I finally found a 3:xx (forgot) Posi from out of a station wagon and kept it. It was a GREAT road car, but not really a full-blown muscle car.
The guy who put the 426 Wedge into Mike's 'Vette had THE most rusted out '56 Chevy Station Wagon I've ever seen. He couldn't put much on the floor behind the front seat because things would fall through the holes in the floor!