There was talk about using premium fuel when you do the ISR mod. The talk was in the "3.0 suck" thread. Some were saying that you had to use premium fuel, and some were saying that they never used it and their trucks ran fine.

Well I did the mod last week. I had just filled my truck with regular unleaded.
I drove my truck after the mod, and it was ok. I liked the sound, and was hoping for a little better milage, but as far as feeling anymore power, I really couldn't tell much of a difference. It never really felt like it was getting much more air.
2 days ago, I tried to run as much of the regular unleaded as I could out of my truck, then filled up with premium unleaded. I actually do tell quite a difference. This is the extra power that I was hoping for when I did the mod to begin with. And throttle response is much better.
I will be running premium from now on. I will post my milage after I run through this tank.

 

Good call! I totally agree.

Once again, I think the knock sensor is retarding the timing on the sea level - 4000ft regular unleaded users.

 

Have you also done the deckplate mod? The ISR mod itself won't give you more air, it just smooths out and shortens the path from the airbox to the manifold. The net result is that you should have better throttle response, but not necessarily more power.

Mark

 

I would suggest doing the airbox mod to get the full effect for your ISR.

Also, where can I buy the 3" rubber hose for the pipe to throttle body/AFM connections? Thanks.

Scott

 

I find that the hose is pretty easy to find out here...
Kragen's (or Chuck's, Schuck's, whatever version you have there), NAPA, Pep Boy's

As far as mileage goes...
I can't resist the occasional jump starts enough to get an accurate reading