Whats the same between aYZ250G and H model

[Cabmkr]

I know the forks and the tranny gears, 5 speed/6 speed are different on the 80/81 YZ250 what about the rest of the bike, frame, rear shock cases etc. I picked up an 81 on the weekend but a brakers has an 80 available (parts bike)

Chris   

[JohnnyO]

The frames are different, the H has a slightly steeper steeing angle but a lot of parts will interchange between the 2. I think the shocks are pretty much the same.

[YZ250H]

Swing arm is different.  Axles as well I think 
H has boost bottle G doesn't.
Many parts fit both though.  Have a squiz through the yamaha parts catalogs