performance help

[98streetyukon]

hey guys, im new to the forum and need some help, i drive a 98 yukon 4wd sle 4dr, with the 5.7 and magnaflow exhaust, and i need some help how to boost my horsepower and my gas mileage

when im done adding performance parts, i want to have about 300-350rwhp and still get 14-16mpg

so what parts would be needed to do this?

no n20

[96Yukon]

Welcome to the board.

Just above this post is one that talks about some of the questions you have.
http://www.fullsizechevy.com/forums/showthread.php?t=84561

Also try the search button. Search Forums. There are many posts on this.

I would suggest getting a turbo or supercharger for the performance you want.

[chevy_ss_383]

one of the guys i went to school with built his enigne in class for his 91. bored to 355, 9.75 compression, vortec heads, bigger cam (i dont remember lift and duration) and various other little things for about $1800 in parts. it dynoed at just over 325 hp, 400 tq. he said his mileage went up from about 12.5 to 14ish. since you have multi port fuel inj, youll get a little more power out of it and mileage too. also consider roller rockers and lifters, performance bearings....anything that will reduce friction. youll also need a transmission. either upgrade it while doing the engine or be prepared for an expensive rebuild.