Systema FTK for G&G GR-25?

[GroundNPound]

Just looking for some confirmation on this matter. I'm looking to upgrade the mechbox on a recently acquired G&G GR-25. I believe it is a V2 mechbox but with a longer nozzle. Looking over the FTKs from Systema I'm curious as to which one is the right one for this gun. I'm wanting a M130 spring which isn't too hard to figure out when reading the info on each kit but which Armalite variant is the appropriate one to go into this weapon or does it matter? I'm seeing M16A1/VNs and M16A2s and of course the corresponding M4 variants which I would assume are not the proper kit for this particular case. I would also like the kit to be a bore up one not high speed as the rifle doesn't even have full auto capability. I'm also getting a Prometheus 6.03mm 590mm tightbore to go along with the mechbox upgrade and a Systema motor to drive the new mechbox. Any insights will be appreciated.

Thanks,
Rick

[Danke]

Measure your cylinder, nozzle, and tappet plate.

Or find out what G&G based it on.

If they copied it from Classic Army I have a bore up kit in hand that I don`t need.

[GroundNPound]

Will do. I'll grab those figures as soon as I can.

EDIT: Sorry, the gun is in the shop right now being modded to stiffen up the QD silencer and I haven't been able to check the mechbox at all. I'll see if I can't find the info online somewhere.