You can use any clutch you want provided you have the proper flywheel, clutch and P-plate combo.
So if you wanted a M5 clutch in the 318 then you need to change all 3 components.
I do know OBDII 318is have a deul mass flywheel that most shops will refuse to turn so will need to replace all 3 anyway which ='s to a 328 cluch kit for a upgrade at no additional cost.
Not sure about your OBDI counterpart but if a different part # then I would think that the flywheels may be different and not an interchangeable disk and or P-plate.
"They say ignorance is bliss..... I don't know what the Fu*k that means but I'm pretty happy". Ricky Trailer Park Boys.
Current Mods....X-Brace, Stromung Cat Back Exhaust, 17/225/45 M3 Replicas, HotBits Adjustable Coil Overs, 40% LSD 3:91 Diff, E30 Gearbox, Boosted.