71 gmc 2wd 3/4 ton p-up wheel size?

[gmc1971harwich]

ive got a 71 gmc 2wd 3/4 ton pickup with 16.5" 8 lug wheels that are rusting out and i want to find different wheels that are the same size from a different pickup. so i can reuse my tires. does anyone know which measurement i have to look for to get an identical size? i dont know how to measure the lug offset.

[jrdv]

Look for some late 80's to early 90's 4x4 3/4 ton ford rims. They are 16x8 and have the correct offset ( at least for my 71 and 72 4x4's ).
I know you want to reuse your tires, but I don't know of any factory 16.5 rims that will work, but I am sure there are still some aftermarket rims available in that diameter.

john