91 non roller 5.8 to 94-95 roller 5.8 swap ?
 

The short answer to each question is probably yes, it depends on what transmissionyou plan to use.

5.8 trucks didn't really get a widespread maf up grade, and finding a 5.8 truck computer that is tuneable with e4od controls is kind of a unicorn, only place to find one afaik are certain govt/cali emissions 95 models. People speculate that a stock 5.0l maf computer will run a stock 5.8 without too many issues, but make too radical a cam swap (lift, lobe separation), or start adding in other bolt ons and you're looking at injector upgrades and a full tune.

If you plan on just using the stock roller cam out of a 94-97 5.8l then you should be fine on speed density, but I would try to get the computer/harness associated with the engine as well, to compensate for any sensor configuration changes.

The easiest way to convert is to keep the original harness with the engine, and lay them into your truck. But I don't think you'll see enough real improvement to justify the effort. With normal maintenance, a stock or direct-replacement engine will run about as well as any "tuned" replacement. If you want a noticeable change, change to a modern engine. Even a 4.6L would be a big improvement, in every way that matters.