The '79 and '80 Drifters used the Arctic Cat Hex clutch, as did the previous Inviter and Intriguer sleds.
Finally, Kawi used the Kawi clutch on the '81 Drifter.
But, it has a different offset.
I think the Intruder/Invader style would bolt right up to the Drifter crankshaft, as long as you use the proper attachment bolt and washers. The Invader/Intruder has a - .200" offset, meaning it sticks out further away from the engine by that .200" dimension.
The Drifter used a flush mount clutch.
You would just need to scoot the engine towards the recoil end by .200" if you use the Intruder clutch.