Center diff, with 2nd gear locked tranny
 

I have a Revo 2.5 chassis, stock tranny locked into second.

I want to use the Traxxas center diff., I would need the diff., the shorter output shaft.... and do I still need a forward only conversion kit?

thanks

I would do it....

did you lock the tranny in 1st gear yourself? if so I would have installed the FOC at the same time the reverse gears are weak and if you are using the RCM mount you will have motor breaking and reverse since you will have the tranny locked

^+1. The stock reverse gears are quite weak. You have to be absolutely sure the truck isn't moving when you switch to reverse (which is the primary purpose of the Optidrive unit) or you'll strip those gears. At any rate, the FOC is required with the CD.

ok thanks