Proto 2000 GP18

Greetings,

I have a Proto 2000 shell of a BN GP 18 I picked up at a consignment shop.

I would like to find a powered chassis now.

Anyone know if the powered chassis are the same for the Proto 2000 GP18, GP7, GP9? Looking for a perfect fit.

If they are the same I would have alot more options in finding another roadname I could use. I am looking for a Northern Pacific unit I can swap shells for variety.

Thanks,

Mark in Texas