Ok just to update, forget it! this trucks wheelbase is just too short for 4s, I know this is really an 1/8th buggy setup, so not surprising really. I dropped the diff oil down to 3k and put the punch control to
90% (first tried 30, then 50 , then 70) and STILL cant stop the front from lifting, problem is it happens at about 80% throttle where its already going at 40mph or so, so once the wind gets under it, its gone, flying through the air.
Dog bones are UJ's both ends, they are 1/8th uj's I made a collar so I could fit them to the front and rear diffs, the shafts were then cut and welded at the right length, the center diff is obviously 1/8th, not the original crt one.