well you made it kinda hard for us...kinda hard to recommend a good oil/piston setup when the thing pukes its guts everywhere after landing one hit.
Otherwise, I know a 4-40 bolt fits allright in the heim joints Traxxas uses. Up on top, see how the Associated shock bushing fits in the shock cap. If that doesn't work try packing a chunk of nitro fuel tubing into the mount on the shock cap and using that as a bushing. What I wouldn't do is try to thread the Traxxas shoulder bolt into the shock tower, it'd probably fall out and tear up the holes in the tower on its way, and now you need a shock body and a new tower. Once you get the shocks on, cycle the suspension and make sure the driveshafts are still fully engaged in the diff outdrives at full rebound and nothing's binding through the full range of motion.