bore up cylinder tune up kit for classic army G3

well the title says most i just don't know whether its the ksg1 or whatever it is
http://www.airsoftpost.com/index.php?cPath=24_67_346

Why do you want to bore up your cylinder?

im getting a barrel thats 650mm long and need to get better internals for it to do work

gentry wrote:: im getting a barrel thats 650mm long and need to get better internals for it to do work

Okay... Then I understand getting it.

You will probably need http://www.airsoftgi.com/product_info.php?cPath=31_52&products_id=1634 along with a M130 spring.