I recently obtained a 1990 Ford Ranger XLT long bed 2wd with a 4.0 liter V6 with a four speed auto. It runs fine. I am planning on getting brand new spark plugs, oil filter, air filter, oil, and some other basics. Any suggestions on brands that are far better than others? I am also planning on putting about $400-$500 into it for better performance. What would be the cheapest way to go to get the most. I did a little research at truckperformance.com and found that the following upgrades are possibilities and their supposed stats increase:

GIBSON Swept Side 2 1/2inch Aluminized Steel Side Exit Cat-Back Exhaust System $267.75 +10-15HP +26 Torque
CARSOUND Universal, High-Flow Catalytic Converter (Rear only) $75.14 +8-10HP +12 Torque
PACESETTER Black Painted 1½ Inch Mild Steel Header $220.97 +7-9HP +8 Torque
BBK Single 66mm High-Flow Replacement Throttle Body $202.48 + 15-20HP +20 Torque
AEP-JBA Blue 9mm Custom Fit Power Cables $55.30 +5HP +5 Torque
BELLTECH Front 1-1/4 inch Diameter Sway Bar $134.23 - -
Magnaflow Performance Muffler $100.95 + 11HP +15 Torque

How do these upgrades look to you guys? Any other suggestions or comments?

I'm a firm believer in, you pay for what you get, but I also like things stock

Well, I've thought a little more and came up with this new game plan:

Flowmaster Super 40 (I know it makes some noise but what about power?)...............$77 @ justflowmaster.com
Gibson Sidesweep 2.5" Aluminized Steel Side Exit Cat-Back Exhaust.........................$267.75 @ truckperformance.com
B&M RACING ShiftPlus Electronic Shift Improver.......................................... ............$37.46 @ truckperformance.com
Helix Power Tower Plus Throttle Body spacer............................................ ...............$78.95 @ performanceproducts.com

I have heard questionable things about the Helix but the science appears to work for me. Also would this be a waste w/o getting the headers because the best deal for quality I could find was BBKs for $370. What about the performance stats for the Super 40?

oh ya... What about the installation costs for the exhaust system sine my friends and I don't know how to weld.

I installed the Super 50 from http://www.autopartswarehouse.com for like 236 or so i can't remember i was kinda disappointed in the sound but makes good power for midrange...I am thinking about taking the 50 off and putting a 40 on so if anyone can tell me yes or no please do...

Installation is do it yourself on my ranger (94) alli had to do was cut the offsets off that were on the hangers then install it yourself sure you could get it welded but you can buy exhaust clasps that make a full 360 around the pipe they say it is 'like a weld but not perminate' so all the toold i need was a saw a eletric saw and a wrench ohh and a buddy would help to it took about 3 hours by my self just doing what i felt like doing....