Originally Posted by
JDNSW
As far as I am aware all the 2.25 engines will interchange without issues except as noted above. Series 2a was fitted as standard with the smaller clutch, but the larger one is a straight replacement (and optional, so you may already have it). The late engine flywheel may not be drilled for the smaller clutch, so use the larger clutch, but note that the clutch cover (pressure plate) is different from the S3 for the 2a, having a spacer on the release fingers. Just a matter of buying the right part, and you probably want to replace it (and the driven plate) anyway while the engine is out.