If you're going to make that much of a change of the pedal stroke, I would strongly advise adding an under-floor power booster. That will allow much better stopping ability in case his leg strength is also compromised. Also, if a conversion to disc brakes isn't on the menu, at least figure out a way to install self-adjusting hardware to keep the pedal height up near the top. That isn't a terribly difficult conversion to do.

"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!
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