You'd definitely need some good ceramic coating to keep the heat in. You'll lose your cats so the exhaust will be MUCH louder. You'll also need to get a Y-pipe. All in, you'd be right around the cost of these:
http://www.dougthorleyheaders.com/t...ilverado-sierra-long-tube-tri-y-headers_15730
They're what I have. They're 14 gauge (versus the 16 gauge of the Pacesetters), have multiple layers of ceramic coating and include a Y-pipe. For the money and with no other or minimal mods, I think they're the best bang for the buck. The tri-Y design is like the best of shorties and long tubes combined, so you shouldn't really trade low-end power for top-end or vice versa. Again, no cats so expect some noise. They don't tick at the collectors like long tubes tend to do, or, at least, not as loudly. My guess is the design breaks up the pulses which attenuates that. Depending on your year model, you might have to modify the Y-pipe where it connects to the rest of the exhaust. Other than that, I had no problems at all with fitment. Over two years and 19K miles on 'em using stock-replacement bolts in the heads. The only issue I had was two of the three bolts in one of the collector flanges worked loose and fell out. I can't say for sure if this was my fault, though. I could've not tightened them enough.