[blykins]

A gearbox with straight cut gears will make more noise. Helical or spiral gears are much quieter...that's why when you put your car in reverse, you can always hear it whine...reverse gears are always spur (straight) gears...

It seems like a straight cut gear box with no synchros would be a pain in the butt on the street...You'd always have to match revs. It's definitely do-able though. There's nothing that sounds better than a straight-cut gearbox whining through the gears though.