VG30i is a snail...

Should'nt all of your plugs have looked the same? The truck is probably slow because its 20 years old. I wish that my truck was faster, but I am happy just easing it around.

When I got my truck, it was running sluggish. I opened the distributer cap, and the rotor was a total wreck. After replacing the cap and rotor, it has run much better.

What kind of miles are on it?

tthe v6 only has 25 0r maybe 40 extra horses..
if you take in account of the extra weight involved it is prollie close to 25 ..

but read the codes and start with a tune up..

properly inflate tires .
check brakes for dragging ..
and lighten the load..

The VG30's were rugged and dependable, but never fast, especially in a truck body. The 160 or so HP is just enough to get the 2 ton truck moving and if it's 4X4, it's that much worse. I wouldn't remove the cat. Do an exhaust back pressure test; if it fails, then replace it. The cost and effort of installing headers will probably not yield enough in power to make it worthwhile to you. If you want it faster, then look into an engine swap: 4.3L V6 GM, VQ-series Nissan...if you really want to get into that much of a project. Otherwise, stick with NGK and genuine Nissan tune-up parts and bump the ignition timing about 3 degrees over the stock setting...that usually "wakes them up" a little. Make sure there's no "pinging" afterwards.

forget my newbness, but bumping the timing is done how? remove the dizzy and crank the engine 3 teeth, then replace the dizzy? I wouldnt mind kickin her up a notch this way. I love the 4x4 on this truck, it really conqures a lot more then most would imagine.

Warm up the engine to normal operating temperature, install a timing light, adj. the idle to spec. (m/t: 800 RPM; a/t: 700 RPM in "D"), loosen the distributor hold-down bolt, turn the distributor to 15 degrees BTDC and tighten bolt (factory timing spec. is 12 +/- 2 degrees BTDC). Road test and listen for any pre-ignition detonation (ie "pinging"). If none, you may be able to dial in another couple of degrees of advance, but I wouldn't go over 18 degrees BTDC. Factors such as quality of fuel and carbon build-up on the top of the pistons (which can increase compression slightly) play in to just how much you can advance the timing before "pinging" becomes an issue.

wow, that works, I will try that maybe this Sunday. I will let you guys know how it works, maybe a few pics will be in order.

The big clue here is the condition of your sparkplugs. Some cylinders are rich and some are lean (black = rich, white = lean).

I'd guess that you've got some clogged fuel injectors, which is leaning out those cylinders. Then the O2 sensor sees the lean condition and richens up the mixture, making cylinders with good injectors go rich.

You can try using some injector cleaner for a few tankfulls. If that doesn't work, you might want to think about pulling the injectors and having them professionally cleaned.