That is the one problem with E power, they use bigger props. I had to make new gear when I did a e conversion on a 60 sized plane. I had to go from a 12 inch prop to a 16 inch prop. Had to make new gear that was 2 inches taller.
If you can find a 12X8 3 blade prop, it will give you about 7 pounds of thrust. So, how much does your plane weigh?
http://www.cermark.com/products/EMP-...12x8-prop.html
http://www.valuehobby.com/product_de...44&item_id=435
Buzz.