Thanks Nate. I'm trying to repower two Rivarossi C-Liners, and the Atlas GP9 has the right wheelbase, and can be fitted with the front AAR-B truck, which just leaves the rear truck to sort out. The 6 wheel Atlas trucks all ride higher that the 4 wheel ones, with the exception of the RSD truck and that's too short, hence why I was look at the PA ones.
Simon