I'm running a 500 inch caddie in mine and plan on driving every day,I can understand if you drive the truck as a daily but if you drive to local car shows and occasionally drive to a long show more than 500 mi can't see changing it .
In 76 when the gas crunch happened a few of my friends took the v8 out and put in a 6 cyl and never went more than 100 mi all year To save gas money
Run what you want I think that 6 will be fine.
Frank
