I haven't had time to take anything apart yet, but I'm thinking the same way. I want to keep the bike (long enough for my grandson to ride it with me-and he's not 6 yet) so I want it to last, so I'm thinking I should do that just to be sure.
Skippy,
Have you considered putting in the late model version of the 120r for the older models 02-06 since you can do the R&R yourself it means you would only need a vpc for your existing clutch, and a throttlebody

Might be about a break even on cost and then you wouldnt have to worry bout having a really built motor "race" so to speak. The newer model motor 120r runs pretty darn good in stock form

other considerations might be
I would definitely consider an r&r of the bottom end then from there >
Axtel 107 mountain motor kit with flat tops and 570 cams, mine without headwork made 120/107 tuned by doc with true duals and stock throttlebody.
I am sure we could have made considerably more power with some head work and a little compression say 10 to 1.
Another good running motor is the 117 if you have the motor down its just a matter of cutting the cases then and adding a timken if your so inclined.