i could be wrong but the clark transmission should be a SAE bell housing. probably a SAE #2, you can double check by measuring the bolt circle diameter or distance between bolts if it is a circular pattern.
if that is the case then you will want to find a IDI to SAE adapter. they are not super common but they are out there. that should get you to be able to bolt them together. i am not sure how the clutch would work. you would probably need to talk to a good medium duty parts guy.