So I just threw on a set of new tires and they feel like there inhaling the power from my little 4.2 V6, mind you, i'm on 22" wheels and 305-45 rubber.. They measure out to 32.6" exactly opposed to the 31.x" I just uninstalled (305-40 extra worn lol), so I got to thinking.. What would be a instantaneous benefit from the extra weight and diameter of the tires I just added, naturally, and it has led me here. I have a base model (XL) '05 with an M50D manual tranny; no idea what my rear-end is now but i'd guess its the 3.3x open differential? I'd like to upgrade to a limited slip setup somewhere in the 3.73 range, basically attaining the factory gear ratio or slightly better.. Don't wanna be revving super high as I do a good amount of highway driving, so what would you guys suggest? How much will this swap cost approximately? and the overall question, Will it be worth it? Thanks for any help! -Yamaha

 

I wouldn't hesitate to put in some 4.30 or 4.56's with the V6. I'm running a 285/70/17 which is about 32.5" with a 5.4 and I've thinking either 4.10 or 4.30's.

 

For your amount of highway driving...4.10's ...4.30's max if its 2wd.....4.56's on that tire will not completely kill your engine but will kill your tranny...if you were doing all city driving...maybe the 4.56's but still 4.10's with a 33 is what i would do

 

Stick with 4.10's with a manual - the OD ratio is 0.8 instead of the 0.7 on the automatic.

A set of 4.10's and an Eaton True-Trak will set you back somewhere around $1200 installed.

 

What about keeping my open differential and just gearing only..? That would reduce cost quite a bit i'm sure, but i'd be longing for the LS still... What would my RPM's look like with 4.10's say at 70mph highway cruising?

 

http://4lo.com/calc/gearratio.htm

4.10's at 70 with 33's in OD is 2337.

Subtract about 500 bucks for no Truetrac. You can buy a factory LS for less than that, but I'm of the opinion if you are gonna do it, do it right. The Truetrac is a gear-operated LS rather than clutch-operated.

 

I understand your point of view.. The thing is, I don't have gobs of horsepower, and I don't need a limited slip differential. It is just merely a want, so with that said where would be the best place to pick up a set of 4.10's possibly with the factory LS diff? What else would I need? Install would probably be somewhere around 200-300 i'd assume? Thanks guys!

 

In your case, I can actually agree with saving some coin and not getting a LS. Most of us guys in northern climates love the LSD for traction in the snow and ice. Being as you're in FL, and it's a 2wd street truck, I don't think a LS is all that necessary, but that's just me. Unless you want to lay down two tread marks when doing a burn out , LS is not really needed for you. As mentioned earlier, I'd get a set of 4.10's, maybe 4.30's and call it a day. Your truck is more wheel than tire, so the weight shouldn't be too bad. I think 4.56's would be too much gear.

 

The Saleen guys seem to run 4.56 gears. I plan to do the same when I run 305/45/22s. I have an auto and 5.4 too