31s with no rubbing, 33s fit well with minor rubbing on the radius arm full lock, depending on the suspension sag.
give a quick search for 351 performance theres tons of things about them. one problem with these trucks is the ECU odb1 systems have to be burned with new chips. theres quite a few upgrades for power but for true HP gains you might consider a piggy back system compatible with your efi set up. Gear change is always a simple upgrade to get some more speed off the line or better towing set up.

 

The e fan can net you around 20hp. Dual exhaust is fine, but remember the F.I. was designed and runs best with cross pipe or h pipe type configuration for better scavenging. Timing bump is a must as well. If, and I don't know for sure, 35hp is the difference between the svt and stocker, you'll get that with a full tune up and efans. Plugs, wires, cap, rotors, seafoam, injectors cleaned, fuel filter and fuel pumps functioning properly.

 

as a fun note look at how much room the efan conversion gave me on my 5.8 l....i used the Mark Viii fan and it almost looks stock when mounted....Dual exhaust will be in my future after i fix my throttle position sensor and MLPS to make sure its not my transmission thats acting funky but the electronic input(have codes for both when i check)

 

33s run fine on my 95 with no rubbing on stock suspension, but it's a 4x4, so it may be slightly different than yours.

ETA: really want 4.10 rear on mine, 3.55 ain't quite the bees knees.

 

You'd be moving backwards in all honesty. Your 95 truck has a roller block and the lightnings came with a flat tappet camshaft. Plenty of aftermarket options are out there that are better than the lightning. Your intake, heads and camshaft is where you want to upgrade.

Intake: Edelbrock Truck Intake

Heads: Plenty of options in all honesty. GT40, GT40p, Aluminum Aftermarket Heads. Most anything is better than your stock heads. Consider your smog setup and header/manifold setup if you choose to go with GT40p heads. They are set up a little differently than other heads. 96-up GT40 heads don't have smog ports as well if that's something you need to consider for your setup.

Camshaft: Plenty of options again. A mild aftermarket roller cam has better specs than the stock lightning cam. The lightning was a beast in it's day, but there's just so many options out there that are better now.

As someone mentioned earlier, what are your HP/TQ goals?

 

Ill have to check out those 31s. Ill probably be doing some work to it this weekend. Im lookin for 300/400 hp somewhere in there. Not to crazy but enough to have fun with. Its only 2wd so I wont be doing to much off roading with it.

 

Just curious what kind of costs are involved in say GT40 heads and a new cam that is decently mild but yet good gains? I have a shop who would do the work for about $60 an hour. Thoughts? Also my 0.02 I would do Long Tube headers. That should gain you about 40lbs tq down low. I want to do that to mine bad but I'm out of $ right now

 

A set of GT40 heads is about $300. A mild (roller) cam is about $270-$300.

Edit: Keep in mind that the GT40 heads might need springs, retainers and machine shop work, which may add another $300+ dollars.