KJA:

A du-bro prop nut (chrome plated brass) can be used to balance out a slightly tailheavy plane.....I've used them before with great results. You can use an electric starter on them as well with the regular insert (standard size) with no problems.

[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXE191&P=7]Du-Bro 1/4 x 28 Prop Nut[/link] <--- that one is used on most 40-46 size motors but double check your thread size

I have been using the du-bro prop nuts for over a year and haven't had any problems. Actually makes a prop change very easy as you don't have to mess with the plastic spinners. If you like the look of the plastic spinner you could use the weighted prop nut under the plastic spinner (would have to use a fairly large spinner 2 1/2-3").

Madd_Maxx