I have tried the back-cutting and drilling of gears, mostly on road race motorcycles. The best luck I had for motorcycles (also with full synchro gearboxes) is to undercut the dog teeth slightly so the synchro engages quickly and securely. This allows for full-throttle up-shifting without the clutch and, occassionally, downshifting without the clutch too (very carefully...don't want to swap ends).
So, do I want to drill/back-cut/undercut gears on a street car? I don't know yet. Its not like I have a tow vehicle follow me everywhere should something go wrong.
I am hoping, however, that the Alfa transmission can be built in such a way that it will last a few hundred thousand miles without another rebuild. BUT, I don't want to have to baby it. Heck, even my Ducati transmission could take some
abuse. I think (and hope that) my expectations are reasonable even for an Italian sports car.
One other thing....I have a co-worker who owns a '60's Ferrari (something SWB) that used to blow rear end gears every 1000 miles or so. I suggested that he buy some new gears, then have an AMERICAN gear manufacturer reverse engineer them and make a set their way. He was worried the the Ferarri purists would shun him, but he was spending a fortune to keep his car on the road. He decided to try it, but not tell them. Well, that was 1991...He has never had to replace the rear end gears again. There should not be a reason to expect less than the best quality when it's your money on the line. Let the other guys (and gals) blow their money/time/effort on inferior junk (to be "pure"). I prefer THE BEST, MOST RELIABLE, AND FUN TO OWN vehicle(s) I can afford, even if they're not truly "pure".
OK...Off my soapbox now.
Oh yeah....The other reason I'm so anal about all this....I'm a mechanical engineer who designs things that absolutely cannot fail for any reason. That's right....6-sigma is too loose and will cause too many people to die. My company has to go far beyond 6-sigma (that's 3.4 defects per million opportunities, or 99.99966% yield for you non-math types) or we will be out of business.
Could I design a better transmission that fits the same envelope and mounting? Maybe. Do I want to? There aren't enough Alfas around to make it a good business decision. It would cost a lot (really a lot) unless I could manufacture a million or more of them and not get sued by whoever holds the rights to Alfa. Then the testing, DOT approval, CARB approval, and possibly European approvals would have to be obtained. As of today, it wouldn't be worth it. But ask me in a year, who knows
Thanks - I continue to await your replies...