I have in contact a gearset manufacture that can make gears, the price for a set of straight cut 3rd gear will be around 400$ or less, the manufacture have contract with Honda, Bombardier etc is a big enterprise, they can make me some set of gears if I get enough people for it.
Last time I spoke with PAR they still offer helical gears, didn't go into detail with them as if its modified helical profile or not but they claimed that side load will break the tranny eventually.
He would know, this dude eats through PAR gears like fat kids eat cake! (birthday)
But really he is the only person I know of to have trouble with the gears, there was a 323 with a msp engine in puerto rico and it was making mad hp. It had PAR gears and the gears didnt break but they split the tranny case in half!!!!! So what im trying to say is that im sure he knows what he is talking about.