I'm running G2 Gear and Axle spacers on the rear of my 67 with 22" GM Transit wheels. The fact that the rear axle is narrower required the use of a spacer (1.5" if i remember correctly) and this also solved the hub size issue. I got mine from Summit.
No spacer required on the front. I've got the CPP Modular (narrowed track width) drop spindles and a CPP disc brake conversion up there.
Truck isn't in the nosebleed section anymore, but didn't want to let the cat out the bag yet!