What exactly happens to performance (especially say on the track (DE)) when a stock /4 sideshift tranny is used in a stock 914/6?

The four cylinder transmission is geared taller because the four has more torque down low. Plus the taller fifth gear will make the engine turn slower on the freeway, so the fan doesn't spin as fast.

It will affect the shift points slightly, as second and fifth are shorter gears. Third is actually a taller gear in the six. I don't think you will have a problem with the gear ratios.


I run a stock 4 fifth gear in my six conversion, and it seems to work well. I had an HB flipped and installed for fifth, and I couldn't run at 60 mph without sending the oil temp climbing.

Why don't you convert the six tranny to sideshift?? It is easily done.