Since the only drives that came with an 898 were the MC-1, then, assuming the gear housing is still original, a kit for an MC-1 would be the one you need. The only difference between the MC-1/R kit and an MR/Alpha One kit is the water pump base. All the rest is the same. So if you don't need a new base, anything from 1972 to 1990 is good.
BTW, when you do the replacement, DO NOT put the 'o' ring on the top of the drive shaft, leave it off, even if there's a groove for it.
Chris.......