I want to say a 1 ton flywheel/ clutch had a different bolt pattern (flywheel to pressure plate) than 1/2 ton. I used a 216 flywheel from a 1 ton on my 235 (so I could keep stomp start; 139 vs 168 tooth, not 1 vs 1/2 ton) that I put in my '49 1/2 ton and I think I had to use a matching 1 ton clutch set. I believe the 1 ton flywheel was thicker, too.