I worked at a Chevrolet dealership in the early 80's when the pick-ups started showing up with the automatic overdrives, the 1/2 ton pick-ups only came with a 305. They had a ton of transmission failures. The engine wouldn't pull in overdrive and transmissions kept going bad. They soon discovered that they needed a minimum of a 3:42 ratio with a 3:73 being the preferred ratio. This was in Minnesota / Wisconsin area anyway. We had a fair amount of hills and this does make a difference. Just my opinion with a 283 I would either put more gear in it or go with a TH350.
