Do nothing to your Jimmy.
You can start simple and add a K&N air filter and a 2.5 exhaust system. After that you can work on the transmission as to replacing the boost valve with a 0'490" boost valve, and the replacing the servo with a corvette servo in you transmission. Yes it will give you more of a firm or say harder shift, but will make your transmission last longer. Still have the original one in my jimmy and has over 365,000 miles on it now. After that you can remove the Screen from your MAF sensor. Just remove the MAF from the air intake tube and place it on the bench screen side down. With a screwdriver, snake it through the MAF without touching the firmament and tap the screw driver with a hammer to break the screen free working your way around the MAF. After place the MAF sensor back on and reconnect the wires. This will give you more HP and free to do. There is another mode to your throttle body blades, but your going to have to get your hands dirt and consist of cutting the throttle blade restricter plate out. You can ask me more about that if you would like to do that, other then that, having the engine dyno tuned. Dyno turning is expensive and you really don't need to do that if your just in to being above the rest without spending to much money.
You can try with removing the screen from the MAF first since the weather out side is bad and that's the easy thing to do, and here is a link that can sell you a modified throttle body blade if you like to keep yours as a spare or pick one up at the Salvage yard for $5.00 and take the baffle plate off.
http://www.cfm-tech.com/chevy-vortec.htm
It give you more throttle responds on the bottom end. You will notice an improvement on your throttle responds and need to get used to it and you may want to buy a B&M shiftPluse electronic improver if you can not Dyno tune your engine and transmission to recalibrate the extra HP on the bottom end.
The B&M Shifplus Kit Psrt #70380 has the step by step instruction and all you really need is a pair of pliers to hook it up. Good luck and keep me posted, be glad to help you get more out of your ride. Here is a link for the B&M shift plus, I have also installed it in to my wifes Montana and a few of the guys here have them installed on there Cavaliers and Cobalt.
http://www.bmracing.com/SPECIALS/Shi...mprover-for-GM
Things done on my jimmy.
Dyno tuned
MAF and throttle body blade mode
Swapped the rocker ratio with 1.6:1
Transmission mod 0.490" boost valve, Corvette Servo
Re-calibrated shift points. 1-2 / 3,800 RPM, 2-3 / 4,400 RPM, 3-4 / 4,800 RPM at WOT
ZQ8 steering box and Corvette vacuum boost for the brakes
cross drilled rotors and ceramic brakes.
