5.0l seems under powered

[cashmoney37]

i have a 2000 mountianeer 5.0l. it has tq headers, mac intake, flow master exhaust, removed rear cats, 4406 swap, new plugs, wires, pcv, fuel filter, 7in lift 33x 12.50 tires. my truck just seems to not have as much power as i feel it should have for everything i have done to it. the truck runs great no noise or smoke. gets 10.50 miles per gallon. the truck has some power but i feel it should be a little more, and excpecially when the a/c is on.
my fan is a little loud at certain rpms. i dont know if i am just so use to my truck and its in my head. but i can not spin my tires at all on pavement. i figured with the 5.0 it would have plenty power to turn some 33's

 

[Turdle]

OK, the mileage seems a bit low. It would be nice to datalog the 02 sensors-just for giggles
When mileage and performance drops, with no CEL is displayed, I would seriously suspect slow or lazy 02 sensors.

 

[nssj2]

Well one slight issue with the cats. removing the rear cats plus the new headers means less back pressure. sweet, at high rpms. Low rpms, needed to begin a burnout, need more back pressure. Unless you changed your stock axles, you have 3.73 gears. Those plus 33" tires do not get along too well. Trust me, 4.10s were night and day when I had 33s. I could light up the rears in mine after swapping to the 4.10 axles any day of the week. Gears would be my best suggestion for your next mod.

 

[cashmoney37]

thats what i was leaning on doing next is rebuilding the axels and i was thinking about going with 4.56 gears. what would you suggest for gears. i am debating about down the road maybe puting on 35's.

 

[KPSquared]

33's and 3.73's bring the suck. You need 4.56. If you jump to 35's. then go 4.88's. That is pretty much the whole reason you have no power. You want big tires and the power to turn them, you've gotta re-gear.

www.justdifferentials.com has everything you need.

 

[Fifty150]

Electric fan will recover parasitic loss at the water pump pulley.
Re-gearing makes a huge difference.
Custom Tuning is like night and day.