9.5 inch pressure plate

[mrmurray]

I'm replacing my clutch ('67 IIA 88" all stock), and I stumbled upon some information that there are 2 different 9.5 inch pressure plates. One for synchro gearboxes, and one for non-synchro. My gearbox is the original D-suffix (non-synchro) gearbox, so the question is do I need to order the pressure plate for non-synchro, or does it really matter. I have in hand a pressure plate for synchro gearbox. The pressure plate that came out looks similar to the non-synchro pressure plate (i.e. different than the replacement one I have).
Thank you!
MRM

[luckyjoe]

The earlier non-synchro release mechanism requires a center boss on the pressure plate. The synchro gearbox uses a different mechanism, and this boss is absent.