Modifying a HB 1/8 diff to use 3.3 sliders

[lincpimp]

According to the pic you posted, if those are modified 3.3 axles, then the threaded portion is cut off, then the groove is milled into the center, and then a hole is drilled at the other end(that goes into the diff). The diff out put gear is held on by a cross pin that slides thru the newly drilled hoe and the output gear has a slot milled in the backside that the pin engages onto. This is just the same as stock HB, so the pin and output gear are un-modified. It could be done by hand, however the hole would have to be drilled prescisely thru the center of the axle. Not sure if you really need the groove, but I think it has something to do with the o-ring that seals the fluid in the diff.