PFF63-418 and PFF63-419 suit both the Upper and Lower engine stabilisers, hence why it is listed as 2 per car for each bush. One pack of each is required to fit both mounts.
PFF63-416 fits manual PG1 type gearbox models only
PFF63-415 fits manual R65 type gearbox models only
Advisory - If fitting the Engine Stabilizer bushes (PFF63-418 or PFF63-418R and PFF63-419) to a diesel engined vehicle, an increase in noise and vibration is to be expected. This should be considered as a performance upgrade, not a standard replacement.