Tires: replacing 650-16 tires with p225/75R16 tires, mud tires, dimensional aspect

Question
I have a 72 Chev stepside short wheelbase pickup that was purchased new by the GSA. It came with 16" diam 5" wide rims. My question is are these rims wide enough for 225/75R16 tires with 6.5" tread. I think 6" wide rims are recommended. I have been running 650-16 6 ply mud tires on the rear that measure 6 15/16" wide on theae 5" rims, but the front tires have a tread width less than 6".

Answer
Bob,

Unfortunately, a P225/75R16 has an allowable rim width of 6" to 7 1/2".

You don't have many options - and one of them would be to knowingly put those tires on the rims, and hope for the best.

I checked some old documents from 1970 and have found that you should use 35 psi for highway driving.  But because the rim is a little too narrow, the vehicle might feel unstable and react to bumps in the road.  Use caution!!