I'm sure I'd have used Helicoils. We used to have a guy in our area that was mobile, something like that would have been the best bet.

jammerrs - Helicoils are essentially repaired threads. You drill the fucked thread out, tap it to a bigger size and wind in a new steel coil, which replaced the thread. Very neat. They come as a kit.

Lightweight flywheels make the engine feel a little more lively, the revs can build quicker, but similarly they can fall faster too, so you really need to shift faster or you'll be out of the powerband. Thats a very broad overview anyway.