maybe to save you some headache down the road, I know how much of a pita it was to drill out the pinion gears to use the traxxas set pins, I ended up taking a stock drive cup and cutting it down, and shaping it as a u joint and mounted it to the traxxas shafts.
What did you have to do to them ?
I'm looking at putting the Revo's on my GPs.
On my trucks, the front Revo will go on fine; but the rear one, doesn't have enough room next to the spur gear.
I'm hoping Mike Hesse can make me some yokes that will work..
on the mad force/twin force axles the pinion gear shaft does not have a hole. So drilling it you tend to wipe out drill bits. Grinding a flat spot deeper does help, both sides even better before drilling. The shaft is hardened so drill bits dull quickly.
Its pretty simple to do really, drill 2 holes in the center shaft, one in each bevel/pinion gear... Then switch your driveshaft so it has a yoke on both sides, then drill out the center of the yokes to slide over the shafts. Cut your shafts if needed to fit. Sounds easy at least lol. I did grind all the shafts as they are a super hardened steel, I used the same drillbit and drilled 5 holes total (one mistake) it just takes a while, like 20+ minutes per hole to actually get all the way through. Once its done though you probably wont ever have to do it again Ive been running them on my Twin Force like this for a couple years now and have had 0 problems with it. Its also quieter, no metal driveshafts clinking around as you drive...
Hand drill and drill press... Hand was actually easier because my bits wouldnt stay put in the press no matter how much I tightened it down. Not my first rodeo Will lol