Upgrade advise for G&G UMG

[lizbob]

Hi everybody, I need a good advise from you. I look to internally upgrade my G&G UMG. What do you suggest ? Someone already tryed to upgrade this AEG ?

I think of a Systema M120 (approx. 350 FPS) upgrade spring and also change the nylon bushings fo steel bushings ? Other parts should I look after to replace ? I just want to change what is necessary. Would you recommended to run the gun on a 9,4 V battery after the upgrade ?

Please indicated me the parts and the brand. I'm living near Montreal, I think I'm going to make the upgrade by myself, but if someone can do it for me, it would be great ? I don't want to improvise, so if you have try a good upgrade with your G&G UMG in the past, tell me your ''receipe''.

Thanks.

[ThunderCactus]

8.4 is fine for 350fps
im upgrading mine in the next 2 weeks, but only to 330 fps for indoor use
I'll let you know how it goes, it'll definetly be better than its current 160-220fps lol