Types of 455's?

[divecop]

Hi, I own a 70, 455 GS. Someone pulled up next to me today and asked if my engine was an HD or something else that I didn't hear. I told him it was the stock 455, no Stage 1 etc. I was unsure if there was any other rating etc. that would answer his question. Does anyone know if there are different types of 455 blocks?

Thanks, divecop

[carmantx]

SD was a pontiac. People tell me all the time that these 455 rocket (olds) engines were great.

As far as I know, the 455 blocks were same, with different compression, cam, and head options through the years. There was a block change for oiling and water passage I think in 73.

Main differences were the stage 1 option.