[C10 - C90 Bill]

If you need pulling power, I would consider a 478 V-6. Which should have been available if your truck was a GMC. The negative would be that parts are getting hard to find for them and they are known to be hard on gas. That said, my '62 478 was amazing. It had torque like a Mack. When grossed out at 32,000 it had no problem. It wouldn't win any race, but it would sure pull. Two other points are Super Tuning and Shifting technique. Not saying you aren't doing it right, but shifting technique is important. I drove more than rode, but there were many times I would ride shotgun and yell out to myself "Shift, Shift"!!! Most of the time I just sat there and didn't say anything. Also again, not saying that you don't, but if you have the gears, be sure to use them all. Super Tuning means getting everything you can out of an engine.

I had a 305 V-6 as well and got an unheard of 15 1/2 MPG Hiway. I also had a 292-6 that performed impressively. Unheard of fuel mileage as well.

No one would agree, but I would also consider a freshly built 292 for your truck. Myself, I wouldn't hesitate.

If I were to go with a Diesel, it would have to be a Detroit, lol.