The stock 964 dual mass flywheel is too large for the 915 transaxle and must be replaced with a special flywheel designed to retain the required timing teeth for the DME, and be small enough to fit in the 915 clutch housing. The stock 964 transmission clutch disc size is 240 mm compared to the 915s 225 mm. There have been reports from those doing similar engine swaps without the dual mass flywheel, of the engine dying due to insufficient flywheel rotating mass, when the clutch is depressed and simultaneously the accelerator is released. (The stock 964 dual mass flywheel and clutch assembly is quite heavy - 43 lbs). The modified flywheel is a bolt-on, and allows use of the stock 3.0 liter pressure plate and disc. The Patrick flywheel requires a pilot bearing, Porsche 901.102.025.01 from a 2.0 liter. The mount for the 964 flywheel sensor was required to be machined by 0.050" to assure the proper clearance (1.0 mm +/- 0.2 mm) from the end of the sensor to the edge of the flywheel. The modified flywheel has a slightly smaller diameter from the stock flywheel.
The clutch used was a stock aluminum pressure plate, and stock clutch disc for the 915 transmission.