When towing with my conversion should I set the air pressure on the van tires at the 42 psi recommended by Ford or the max setting on the tire at 50 psi. Thank you
You have a van conversion, and you're also towing something behind? If so, this means you have extra load on your tires due to the tongue weight of your trailer. Assuming your tires are capable of supporting the additional tongue weight plus your van's axle weights, I would fill the tires to the 65 max to avoid overheating the tires, and for added stability while towing (less flex in the tire).
Depends on the weight you have. Many overload their vehicles, many don't. If your within your vehicles GVWR then use the Ford door jam figure. If your over the GVWR's of your vehicle I'd use max PSI for your tire. Then we have the old chalk test right Marty :B