How to build solid M6
btw, did a search and couldnt find anything
As for the 3-4 fork, any place, like D&D ( http://www.ddperformance.com ) has them.
Other than that, the only real option is to cryo treat the parts. A full cryo on the whole tranny costs about $400 (at least that was my local quote). I chose not do do that.
D&D only sells one level of blocker rings, and everything else is of stock hardness. Rumors of aftermarket parts coming out (like harder / different cut gears), but those are just rumors at this point.
IMO it's a crap shoot. I have a buddy who snapped his T56 main shaft on a launch - but the stock aluminum driveshaft lived. Weird.
I've got one trans with the steel 3-4 fork and the fresh rebuild kit in it right now, and my spare is getting pro-shifted when the parts get back from Liberty.
Pro shifting doesn't add power capacity tho, just faster shifting (no blocker rings).-Andrew

