[Aussie Mike]

You could use teflon lined spherical rod ends on the trailing arms.

I agree with Al, you need to do something to beef up those lower arms if you're going to put lots of power through them. Either add a brace or use thicker tube.

I've seen a few pics on this forum of broken lower arms in Cobras and the drastic results. Not worth taking any short cuts on in my opinion.

Cheers