98 chevy performace upgrades

I am looking for more power please help. I have a 98 chevy C1500 single cab 2wd with the 5.7L(350). So far I have shorty headers, Flowmaster mufflers, Casper O2 sims(deleted both cats. A K&N FIPK GEN2 cold air kit. replaced the clutch fan with a Hayden electronic. I am looking for more power. I bought the truck about 2 years ago basicly stock. I am not sure about the ECM if it has been reprogrammed or not. It doesn't have a top speed limiter. Is there a way I can find out. What is the best reprogramer on the market. i have also heard of guys who can reburn a custom progam into the ECM. I am also thinking about a cam swap but I dont know which one is the best. thank you for any help you can offer me.

I your lookign for big power all those small mods are nice and the exhaust im probally going the same way with mine sick of freakin cats im also looking into supercharger i found one that will bring my truck up to about 400 horses and about 450 foot pounds of tire killing power found a good one that follows the name of my truck engine its a vortech supercharger and rather a decent price 2000 heres the link and have fun http://www.vortechsuperchargers.com/products/yourcar/96-0057truck.html Ps i have a beutiful 98 silverado z71 lifted extended cab third door red 33s intake exhaust soon a performance tranny rebuild and a hypertech chip there one of the best because you can program your trans and engine at the same time

check out gmfullsizeforums.com. some of the custom tuners (westers, nelson, pcm4less, waitformetune) advertised there offer over 35hp and 45lb/ft of torque from a custom tune. that's quite a bit more than hypertech, crane, jet and the others.

go to autozone or something and ask them what the biggest cam is that you can put in without having to get better valve springs. get that one. it will be lopey as hell which sounds awesome, and a side effect is that the vaccuum levels will probably suck when it's at idle. it eats gas a little faster too, but it makes a butload of more power. you cant beat that cool lub dub idle too lol it makes all the neighbors really pissed off