I noticed that alot of small park flyer models req'd like a 400T or a 400BL what does the "T" or "BL" stand for? Also a plane I have specs out a gearbox do I have to use a gear box or can I use a outrunner motor without the gearbox. The model I am refering to is the Nitro Models EP pitts calls for a 400T motor with a 5:1 gearbox and I want to install a E-flite 480 motor without a gearbox. is this wise or do I have to use a gearbox? Thanks in advance

I would not advise using the 480 without the gearbox on the pitts, you would have to use a small prop and you need a larger prop for the pitts
you can just use an outrunner in the place of the gearbox but you need a lower KV motor that will allow you to be able to spin a big enough prop for the plane

I believe he is referring to a 480 outrunner.

T I have no idea what that stands for, maybee torque or something. BL stands for BrushLess. It's just brushless though.