I just recently received my FWI from intense and I also just received my autolite 605'*. I have not done my PCM yet because honestly I will need a little guidance on the settings. I also have my exhaust opened up pretty good.
My question is . . will I get a noticeable difference if I change my pulley to a 3.5. Or would it make more sense to do the necessary upgrades to put on a 3.4 pulley. I don't really want to do a 3.4 because of the possible KR issues. Especially if there is a noticeable difference with the 3.5.
I'm really just looking for some opinions. Thanks

With the mods that you currently have, a 3.5 pulley will make for a noticeable difference. Until you can scan and re-tune to avoid KR, I wouldn't drop below a 3.5 at this time.

If I do scan and I find that I do have some KR. . .what is involved in a re-tune to eliminate the KR

Shoot the only thing'* you DON'T have from Intense'* Stage 1 kit are the PCM and 3.4 pulley. I'd say go for the 3.5 and tune that PCM ASAP.

HP Tuner is what I use. They aren't cheap and the learning curve is steep, but it can sure get more whoop out of your whip!

What are HP tuners selling for?

$500 for personal use.

What if I want to use it on my car?

$500, that'* for personal use. It'* $650 for the pro set-up
http://www.hptuners.com/order.php

I was kidding. I don't want it for personal use, I want it for my car. I am already a tuned machine.