Unless you're planning to do real truck stuff with an antique vehicle, I don't see a problem with using the smaller clutch. There are plenty of good condition used 235/261 flywheels available that can have the clutch contact surface reground- - - -no point in throwing away good money on a brand new one. Just be sure to get one with the 139 tooth 6 volt ring gear. I'd machine a spacer ring for the center hole if I was doing the swap- - - -just a few minutes' work on the lathe and a piece of pipe nipple.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!