03' Sonoma , new here* need help

Hi, a year and a half ago my father purchased an 03' GMC Sonoma Auto pickup. I had always thought it had a 3.8, but after going to the dealer the other day he specified it to be a 4.3L Vortech (only 30K miles, yeah be jealous). The engine says vortech on it (haha I would say block but since I'm an idiot I might be wrong). Anyway, before I start modding this torqie V8 that's missing 2cylinders, I want to know what free quick performance mods there are? I will eventually do the 350crate motor swap from GM from before that I will do intake, cams, headers etc. and even before that I want to know if there are any things I should take out from under the hood for a quick performance mod.
I'm new be easy on me, fill me in on anything I should know about this truck.

also I heard the Auto trannys and rear ends on these trucks eat sh|t and sometimes break with stock HP
thanks

Save up your money for your V-8.

With free you get what you pay for. Pretty much nothing...

Free mods
Cut the half moon of the butterfly plate off (normally you would have to do the EGR mod as this leans it out a bit but the mod is built in to yours already so it would be fine)

Cheap mods...
Ford taurus e-fan
Slightly lower tstat (don't go lower than 180)
Under Drive pully's
Drop in k&n filter

Mid range mods
Headers and y-pipe
Free flowing exaust system (cat back and free flowing cat)
Better muffler (flowmaster etc)
MSD 6a ignition system
Lt1 Edit
Hyper Tech power programmer

Expensive mod
Turbo
Supercharger

the 4l60e tranny on out trucks is awsome, and ive never heard of the rear end breaking unless your matting on that 5.7l

thanks rlith, I will try some of those. Any idea of how much HP gain there is with a mid range intake and exaust upgrade? maybe headers as well? I heard an ez 210 with exaust and headers... just curious

for intake, go to e bay, and buy one of the cai from there, and when you get it if you want to, put a k&n intake on it... our manifolds flow pretty good for what they are, if your going to go headders, go all new exhaust, headers, high flow cat, and high flow muffler, and yes you will be looking somewhere around 210 horses, possibly better, i like to side on caution when adding up, you cant just add the preformence numbers and get a total, those numbers are on stock setups, or setups that benifit that mod, ie, for best results on cold air intake, the exhaust work is already done...