Castle uses the same labelling/ name system for their motors as Neu, so logic dictates that the castle 2028 is gonna be noticeably smaller than the 2230 I'd have thought:
2028 = 2.20" diameter & 4.4" long
2230 = 2.50" diameter & 4.7" long
Didnt take me long to find that info out by comparing the listed specs on the castle website of the neu & neucastle motors...
http://www.castlecreations.com/produ...rs/nm2200.html
http://www.castlecreations.com/products/2028_motor.html