ICS m4a1 retractable front wired changing to back
 

First of all i have the regular ICS m4a1 metal body with no body mods what so ever so i plan to rewire the gearbox to the back and drill a hole straight through the buffer tube and install a crane stock while using the stock buffer tube and stock wiring kit. This sounds like a cheap mod but i dont want to blow 250 just for an ics crane stock and extra batteries so i also need to know what crane stock will fit on an ICS stock buffer tube please leave suggestions as i dont want to screw up my gun.

Magpul moe fits very tight, just my two cents, a full stock would be the cheapest alternative. I doubt a hole drilled into the buffer tube will screw up your gun, I don't even know if that's how crane stocks work.

What type of stock do you currently have on now? You'll need a buffer tube adapter to install a crane stock. Then you'll need to file the left and right side of the buffer tube adapter, for a standard buffer tube to fit, unless you get an ICS specific buffer tube and stock.

You don't need any of that, and you don't need to drill a hole in the buffer tube. There is room for the wires to go out through the buffer tube adapter, and run inside the buffer tube.

Just pick up a G&P cranestock with a 9.6v and you're set. G&P fits on the ICS buffer tube, a little tight but it loosens up after a while..

The only thing you need to do if you want to use the stock wires is add a bit of length to the wires so they reach the end of the buffer tube.