Hint #1: 5 ton and 2.5 ton clutches have different NSN numbers. The military is efficient that way - same part means usually same NSN number.
Hint # 2: The 5 ton clutch disc has a 15" Inch Overall Diameter, 10 Spline; 1 3/4" Inch Spline Diameter . While the spline diameter seems identical, the 2.5 ton clutch has a diameter of 12.880 " nominal (13 ").
Ask anyone that put an LDS into their Deuce - 5 ton flywheel and clutch assembly have to go, they won't fit. The bell housing takes an adapter to mate to the smaller Spicer transmission. Until last year I was regularly moving the 5 ton flywheel from one corner in the shed to the other until I snapped and scrapped it. I can tell you that it is beefier than the Deuce version!
Does that answer the question "can I make a 5 ton Multifuel (NOT CUMMINS) clutch disc fit with a 2.5 ton pressure plate"?