[ILLusion]

Get the front wired version (for M4/RIS) and rewire it to the back. All it takes is one wire approximately 1 foot long to replace the positive wire that runs from the front battery compartment to the trigger switch. Swap that and run it to the back.

Next, take the black (negative) wire that runs from the front power to the grip... and just run the wire from the front out the back. Nothing needs to be cut or replaced - it's just a regrouping.


This is easier, cheaper, and more reliable than getting a rear-wired version. If you get a rear-wired version, you'll either have to:
a) De-solder and resolder new wiring from all contact points leading out the back of the gun = extra money spent on wiring
OR
b) Cut off the battery plug coming out the back and solder on longer leads = insecure splice which could lead to crimping from the added bulk - this could potentially lead to a short circuit and burning battery right besides your face. Not fun.


Besides the wiring, the difference between the front-wired version and rear-wired *may* be the cylinder size. It's weird, I've seen the rear wired version with both a full (M16) cylinder as well as a ported (SR16) one.

If you're not familiar with splicing, desoldering and soldering (to get the Dean's plug on to the new gearbox), this project may not be something to tackle yourself. There are destructive modifications that need to be performed on to your receiver to get wiring out the back.
Although the G&P instructions say to hack a hole to let the wiring go through, there is a WAY better alternative. As long as you maintain 16AWG wiring (or smaller), you can just run them through the buffer tube. A groove will need to be cut in to the edge of your receiver to allow the wiring to snake from your gearbox through the lower receiver in to the buffer tube. Doing it this way will allow you to completely separate the gearbox from the lower receiver. Why G&P suggests the other method is completely beyond me...

As for motor alignment - read any Tokyo Marui manual. It tells you how to adjust motor height. There are also many guides and posts on this particular topic across the internet as well as on ASC. The *best* way to check motor height is to open up the gearbox, remove the spring, spring guide and piston assembly and then close up the gearbox. Screw it up at some critical points to keep it together, then attach the pistol grip, motor, motor plate and grip plate and run it that way. Removing the spring takes all tension off the gears and reduces any misaligned stress against the pinion & bevel gear.