I took the plunge to 4.10 and never looked back.
Honestly, yeah you'll lose mpg, but screw that noise. We drive a v8 pony car, not a Prius.
I dropped to low 20s highway and low to mid teens city mpg. Just run a gear high around town and you'll be fine.
My speedo read 8 high, so you'll need it tuned ASAP.
Gear ratio charts are available for any setup on this web page. Just select your tranny and gear and read the graph.
To get to the graph: click calculators (on the sidebar) > how fast/each gear(7k) > input car specs in drop down lists. http://www.paladinmicro.com/pmicro.php#
Disclaimer: Due to several inquiries, this is NOT my web page and I do not claim any ownership or cooperation with the page. It is simply a reference chart I use for gear ratios and explaining to people exactly what they will get with a certain gear.
My plan now is to put a sc on it. But if plans change in the future I my regret not goin 4.10s. Is there anybody who has had both and recorded times to see I the diff is that big of a deal? I'm not tryin to be a baby about this but I want to get good facts before I make a decision.
Here in the flatlands of Florida I regret not sticking with the 3.27:1 stock gears. I installed 3.73s just after getting the car in late 2006, and then retuned and made minor tweaks that got me up to 262/305 rwHP/torque.
With the lime rock aggregate roads, that wear smooth as glass and the added HP, 1st gear is useless--over before it started. When the tranny gives up I am going with a 2.87:1 1st gear (as opposed to the stock 3650 3.38:1) to fix that and tighten up the 1-2 shift...