Somewhere under there is an Olds 260. Rebuilt in 1992, it's not the original block. That one had to be tossed as after 145,000 it was so badly scored it couldn't be rebuilt. It's bored .30 over and with that Hurst style exhaust I'm thinking I have about 115-120 hp now, as opposed to the factory 105 hp. Great for those times when I'm going uphill doing 65 in 90 degree weather with the A/C on.