No, they have different specs. The GBBR body is thinner and smaller in some areas.

 

Yes, there are multiple drop in systems that convert an AEG to a gas system, Do you want to use gas in mags or an external line?

 

Yes, there are multiple drop in systems that convert an AEG to a gas system, Do you want to use gas in mags or an external line?

Specifically, I want to convert my VFC SCAR to take WE Tech gas/co2 mags

 

http://shop.ehobbyasia.com/ghk-gas-blow-back-conversaion-kit-for-m4-ar-aeg.html

I dunno about a VFC scar (the air nozzle is different) but that thing works in VFC M4s.

 

Polar star makes a Co2 gear box that's drop in for AEG body's but it's $450+$230 for an air rig and $60-$150 for a tank if you have a bear by place that will fill them. I believe there making a conversion for the Masada from AEG to GBB. Other then that I don't think so because the body's are way different.