Re: Question about a 36’ flathead pressure plate.
Check the flywheel bolt pattern. Even though both are 9" clutches, the Mustang pressure plate may not bolt straight onto the flathead flywheel.
No need to pull the engine on a 1914 Model T. The clutch spring can usually be replaced with the engine in the chassis. Just use a proper clutch spring compressor and inspect the clutch components while you're there.