I'm looking for ways to get more power and mpg out of my truck. So any suggestions would be appreciated, I prefer to keep it simple! I have a '05 Silvy ext cab V8 4.8L 294 and I have a flow master series model 40 muffler if it matters? I talked to buddies at work they say to just get a block or bore it out. I've bored out my ATV before and was not happy with the results(went through 4pistons, 2clutchs, 3sets of valves and replaced cams multiple times) so I am a little distrusting to the boring out of the motor.

i was thinking ways like air intake, new exhaust, or other ways. And I wanna keep to like a DIY project.