Does anyone know if the 92-96 american mitsubishi diamante headlights fit an australian tr magna?

They will fit most likely but they will refelct on to the wrong side of the road

Don't see why not, the NZ and Japanese ones do, you may have some initial beam alignment issues due to the different drivers sides in each country.

edit, norby beat me to it

cheers for that I wanted to make sure before i got them brought over from america

If its the ones with the chrome around it then you will need that as well due to the light being smaller. You will need the grill as well. And as others said, the beam spread will be very bad with the spike going towards oncoming traffic. Dont think they are parabolic as well. Better off fitting a set of KS Verada parabolics.

If you want these the best options are

(1) Japanese Diamante lights. same lights but correct beam pattern.
(2) Australian KS Verada Paras.. basically same light but they don't need the new grille and silver chrome surround that will leave a gap on your US ones if you don't get them.

What are you spending to get them here? I have a set I might be putting up for sale soon. Are you in Sydney?

Send me a PM if interested :)