Hi Tim,
Here is the most important question. How do you plan to use the truck? Will it be a daily driver, garage queen, sunny day cruiser? Do you want to drive it on the freeway or stick to back roads? Are you taking it to car shows or mostly to Home Depot? These details will help the experts on the site give you informed suggestions.
That being said, you don't need fuel injection to have reliability. Any of the typical engine choices, including the 235/261, can be a reliable runner. A 3 speed plus overdrive or T5 5 speed will allow you to cruise the freeway if needed. If you want more modern, the next step is a 250 or 292 straight 6. Both great engines, very smooth with tons of torque. If i were you, these are worth a serious look. Jumping to a V8, there are nearly unlimited choices from 150 HP on up to ridiculous. V8 engines in these trucks are a dime a dozen (including mine). They are a cheap way to get power and reliability but not much originality.
This is a fun part of projects - deciding what you want and envisioning the final outcome.
