My 2001 Expy 5.4L 4x4 already has a K&N FIPK, Gibson Cat Back, SC Micro Tuner, BFG T/A KO 285 75 16 tires, and Pro Comp MX6 shocks.
What Next will give me most performance for $?
1. Electric Fans?
2. Underdrive Pulleys?
3. MAF, Throttle Body, Spacer?
4. ??


Any opinions would be appreciated!
Thanks,
Mtnbike_jr

 

If the truck is an automatic, also look into a shift kit. From what I have read, TransGo makes a great one.
The next engine mod that I would do in your case would be what you have listed in the order that you have them. Number 4 should be an ATI Procharger!

 

with the only possible exception would be to consider the factory tech valve body (FTVB) through Troyer Performance. A main problem I had was with a slow 1-2 upshift under WOT. The Super Tuner fixed a good deal of that, but the FTVB *will* be my next purchase. Just do a search on FTVB for more info if you like.

 

Thanks Guys!

I'll check those out...supercharger will have to wait for a while. Though, it sounds like it would be totally kicka$$!

 

Have you considered some new gears? For a 4x4, it'll be a little spendy, but with 33" tall tires, you basically have the effective gear ratio of close to a 3.08!! That is, if you have 3.55's now.

You might already have 3.73's, which is better, but a set of 4.10's would bring you pretty much back to the stock ratio with the 29" stock tires.

You should probably start considering some tranny mods to help with any additional engine power gains as well...... The stock one is fine for stock power, but more power equals more heat and more heat equals a shorter life for the tranny...... Don't know too much about them, but the torque converter and the thing that controls the shifting should be upgraded to keep that heat generation to a minimum.....

Good luck!

 

ok thanks. The micro tuner actually solved the higher gearing caused by the taller tires by modding the shift points based upon by tire diameter. It feels much better than with the stock shift points.
I'll probably get the FTVB mentioned above. I did a little digging and it sounds like a great upgrade. I'll see if I can get a hold of Gregg Evans and see what else he recommends within reason.
E-fans and underdrive pulleys next, then I'll start with cosmetic upgrades. I might lift it and/or supercharge it after it's paid off in 4 more years and I can save up the $$.