Well I got my new motor dropped in (from an '86 Club Car) and just like I thought, the drive clutch doesn't line up quite right with the driven clutch.
Guess I'm either getting a new 88-up clutch or else making a new motor plate so I can use this one.
Illustrated:
*For those of you you may be wondering, yes my cart is an '87, but it has 88-91 clutches. Unofficially, 1987 was a crossover year for the clutch changes. There's another '87 near me that also has the newer clutches.