success!
got the old gear off cleanly. the end of the shaft is flawless so the new gear should go on pretty good with the appropriate amount of heat.
still thinking about drilling and tapping the end of the shaft to utilize a pusher to seat the new gear.
i did discover late last night that one of the push rods is bent. will have to pull it out and do some further inspection to make sure that the valve didn't suffer any damage. guess i should look at the piston as well...
post hoc ergo propter hoc
