Burns,
A G Force or Tusk 400EX axle, is 1" shorter than a + 4 Lonestar, so if you had one of those & then put the spacers on the outside of the hubs it probably would be narrow enough.
I got one of those in my daughters R & even with the 400EX hubs its narrower than a normal Lonestar 250r +4 set up.
Back when I bought that axle, was like 180 bucks to my door & that wasnt a dealer cost price, but retail.
Neil