Polar Star Fusion Engine installed in my G4

I have the FE installed now and it shoots great, maybe just a few more kinks to work out but otherwise I have never been as excited about getting to use one of my guns, I cant wait to take it to a game yes all this is pretty expensive but not as costly as it could have been had I purchased everything brand new base gun is an airsoftgi G4 A1 Hard which is basically a G&G CM polymer bodied M4 with a 10 inch Noveske rail - $ (gun only, this does not include the magpul furniture, light, or