Just remove the timing gear, not the whole cam. The myth that a timing gear can't be changed with the cam in the engine was invented by people who never made a living working on these engines. Drill and tap the gear hub if necessary, use a puller to remove the old gear, and heat the new (aluminum) gear a little to allow it to be tapped on without enough force to damage anything. Remove the fuel pump and use a pry bar to hold the cam forward against the thrust plate while installing the new gear. Back when I ran a shop, I'd fire anybody who couldn't put a new timing gear on a stovebolt engine before lunchtime!
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!