Depending on the offset of the drive crank arm, you may or may not need a different bottom bracket (spindle length, really, but they come as complete units). Cranksets and bottom brackets are usually "matched", and if you install a drive crank arm with a different offset, it either may not press all the way on the spindle before one of the chainrings hits the chain stay, or it may mount too far out on the spindle and change the chainline. (Or, it might be good because it's a close enough match!)

It seems like the mid-90s through the mid-2000s is when the offset was changing on MTB drivetrains. Older bikes tended to use longer spindles and the small chainring was located 5-10 mm inboard of the crank arm. Newer bikes tended to use shorter spindles and the small chainring was pretty much flush with the crank arm. Mixing and matching these parts can produce odd results. It might work out just fine -- but it's something to be aware of as you're installing the new set.