Excellent points, Dave. It's often thought that replacing the blockers will make it start shifting like new. But, If it's been driven for several months with the gears grinding on every shift then more than likely damage is done to the gears as well. I've seen a few, including some of mine, where tooth edges are worn smooth or rounded off on the synchros. I recommend synchromesh with my blockers because the blocker manufacturer recommended GL5 whch is much too thick for the M5R2 so I stepped it down in weight to Synchromesh w/FM. My testing them with ATF, Valvoline High Mileage, gave me excellent results. I recently rebuilt an M5R2 that had gear oil in it. Every blocker in it was worn out including 1st, 4th, and 5th which tend to outlast 2nd and 3rd 2 to 1.