Cab dolly construction question. Warping cab?

[Rob68c10]

I am making the trip to Carlisle all truck nats and will be bringing home a cab hopefully. I plan on building a dolly made from 4x4s because it's a lot cheaper than fabricating one out of metal. My plan was to build it tomorrow night, but my Dad suggested I wait. He said I should wait until a few days before I go, so the 4x4's don't warp real bad. He said that bolting the cab to them will prevent them from warping while drying out. My question is will these 4x4's drying out cause my cab to flex and warp? I would be highly annoyed to find my cab warped later on down the road.