Left home in dark and by the time I drove 7 miles, headlights had faded out. Replaced headlight switch and still no lights

I have a 94 Dodge Ram be 350 with a 5.9 liter engine the key will turn over the nation relay is working but it will not crank it will not start it will not do anything I'm getting power to the starter and everything but I'm not getting any kind of turnover. It started out intermittently but has gotten worse and now it doesn't seem to want to start at all

new blower resistor,switch,and a/c selector switch

Replaced a transmission for the "beast" with a used one. Van runs good while in drive. When coming to a stop the transmission does not drop down to first gear.

I would like to know if p265 75 R/16 would fit on my van?

i got a 35gallon tank