early non ves was bigblock if i remember correctly. ves 600 is a small block. thats why it is the most common swap into the 440 race sleds, less mods to fit, 700/800 are bigblock still.
as far as the xc goes... if you have been riding an xlt (or any wedge) and can move up to an edge chassis with the 600 twin and ves, you will love it.
No sledding this season.... sold them both to pay for a wedding.