Wheel patterns

[Trbush]

I have a 1963 Chevrolet Fleetside pickup truck two wheel drive with a 6 lug bolt pattern I purchased a set of rims 6 lug bolt pattern Chevrolet but they came off of a 2007 the bolt pattern matches up no problem but the rims will not go over the Hub it is too small and the rim does not bolt up firmly against the brake drum I might want to add that my current wheel size is 15 in and the new rims are 17 in what can I do I'm not understanding