jacksonsride

I am looking for the best place to start when adding performance parts to my 99 5.7L Yukon. I already have the K&N, spark plug wires, and plugs. What next? I am thinking either exhaust, Superchip, headers, or maybe even a cam. Any suggestions would be appreciated.

Eggert

Hi jacksonride.
If you have the 3.72 rear end, you could put in the 4.10 one.
This will bring up the RPM and performance, but also lower the gas mileage.
My preference would be not to upset a well worn in engine with drastic changes.
Sometimes engines don't like that.
I had an anemic 1995 Suburban K1500 with a redline of 4000 RPM, and the 1999 with the 5000 RPM redline is quite a bit zippier.
On the upside, I got 16 mpg on the highway.
My performance upgrade was to go to a 2001 Yukon XL K2500 with the 6 liter engine and a 4.10 rear end.
That thing clocks... but also only gets 13 mpg on the highway.
Good luck and take care, Eggert.

KRS62

I just put in a flowmaster and dual exhaust. It wasn't a huge difference, but it's a little more responsive it seems (maybe it's just in my head.) So if you were thinking a "cat back" type upgrade, don't expect miracles. I've got the 4.8. Next for me is the K&N.

KRS