I have a 3.7L 2005 Dakota. Currently with a 68.5mm Fastman throttle body, and Airaid intake, and Gibson exhaust. I have PCSed to Germany (in the Army) and in order to get my truck registered, I have to drop the noise of the exhaust. Well, I currently have an 18" resonator on order and plan to weld it inline before the muffler. So, my first question is do you guys think the resonator will drop my exhaust note from 97 decibels, to at least 95? My next question would be how would the resonator affect my power and gas mileage? Also, since I am NA, would going back to the stock TB increase my MPG and power.....I really haven't noticed an increase in either after adding it....rather a decrease in MPG. I also have an ARE bed cap. Is the weight of the cap negligible in regards to gas mileage, or should I lose it to increase my MPG? Also, how worthwhile would it be to do an E-fan conversion with a 180 T-stat, or should I just stick with the clutch fan and stock T-stat?

 

I would use the stock thermostat but use the electric fans. Return the factory TB to its original place. That larger throttl body you purchased would only benefit you if your intake had a larger opening like the aftermarket TB itself. The mismatched ports between the two is like if you were to use heads tha had say 1/8th smaller port than the intake manifold which is a no no for making power.

The reason I say keep your factory thermostat, is because not only will you use MORE fuel with running a cooler thermostat you will have a less sufficient spark in the chamber also causing less mileage since the EFI engines are sensative to even just5 degree changes or so. Keep everything factory except the cooling fansand usea control switchmounted in the dash.

I hope this helps you out. [sm=hiya.gif]