Let me start off by saying that I'm not here looking for anyone to do all the work for me, or hold my hand and walk me through everything step by step. I'm mainly looking for quality & budget savings. Ok so I've been toying around with a custom V2 gearbox for my M4, I want to build one from scratch, and would like the community's opinion on what I have so far and let me know if I've missed anything. Let me know what you think (I know there are cheaper/better quality options out there, just don't know what they are or where to find them). This was the first list I put together, just running from what I could recall I would need and trying to find parts that fit the bill on ASGI. Systema Reinforced 7mm Gearbox for M4/M16 Series (really thinking that I should go with an 8mm box but not sure which to get) Modify Modular High Speed Gear Set for V2/V3 7mm Gearbox (not looking for outrageous ROF or high FPS, somewhere around 350fps and 20+ ROF would be fine) Madbull M100 Spring Systema Ver2 Metal Spring Guide Action Army High Speed POM Reinforced Piston w/ Metal Teeth (14) Bravo Aluminum Piston Head w/ Thrust Bearings Magic Box Ultra Efficient Teflon Coated Aluminum Cylinder for M4 Modify V2/V3 Stainless Steel Cylinder Head Prometheus Air Nozzle for M4/M16:: Modify Anti-Reversal Latch for Ver2&3:: Rewire from front to back using: Systema Low Resistance Wire set for Type 2 Gearbox Add Deans Connectors to both gun and battery Definately adding a MOSFET (but not sure where the best place to get on would be) Last I will be powering all of this with a G&P M120 Ultra High Speed Motor (Long Type) and either a 9.6v or 10.8v NiMH or a 11.1v LiPO (all depending on what would work the best for the ranges I'm aiming for: 350ish FPS & 20+ ROF) Thoughts? Comments? Anything I missed? This is a second run of a Custom V2 Gearbox from scratch after toying around on Clandestineairsoft (recommended to me by several people) Lonex V2 Gearbox Shell w/ 8mm Bearings, Tappet Plate & Selector Plate SHS M4 Safety Latch (cover) Steel Version 2 Cuttoff Lever w/ Spring and Screw SHS V2 Trigger Contacts & Assembly 13:1 Ultra High Speed SHS Gear Set w/ Gen 1 Bevel SHS Shims - 27 Pack SHS Anti-Reversal Latch SHS Sector Gear Delayer Chip Lonex Plastic POM Ball Bearing Piston Head Scatterplot Sorbo for V2/V3 Gearboxes - 1/8" Thick - 40 Duro M4 Cylinder Head SHS T3/4 Type II Cylinder SHS Nylon Piston w/ 15 Teeth "SHS Blue 15 Tooth" Aluminum M4 O-Ring Nozzle SHS M100 Spring Super Shooter Stainless Steel Ball Bearing Spring Guide for V2 SHS High Torque Motor - Long Speed Airsoft M4/M16 Tuneable Trigger (Black) MOSFET definately My third option would be buying a JG / CYMA Enhanced 8mm Gearbox for M4, instead of going from scratch. IF I was to go that route what all parts on this list could I cut out in order to improve the JG box from Evike? Thanks for any and all help.