It came new from the factory with a 305, but I had it yanked immediately and put in a 327, after a few years I went to a stock 350...but that wasn't the performance I needed...or wanted... so this last engine was an LT1 with all kinds of speed equipment. The temperature gauge failed, the radiator got a leak and I didn't know the car got hot and it had only had 48,000 miles on it when I blew it up....Spectacularly....blew it up I might add. I started it at the tire shop, and it banged very loudly and so much steam and smoke came out the car literally disappeared and guys came running with fire extinguishers, Frankly...I was sitting in it stunned and a guy grabbed me and pulled me out, but it all cleared and the car was idling on 3 cylinders...it was horrid. I literally sobbed for a week...out on the couch, no make up or clothes and just cried. I really had expected he and I would go out together...It not once ever entered into my mind I would blow it up....me!She's had a couple new engines put in that IROC, the last one being a Corvette engine.