A 4.09 would be a bit much for me. I would think that a 3.13 would make a small but noticeable difference.

 

Yes.
Direct swap.
If I'm not mistaken the 250 as well.

~Dv8

 

Do we have any available swaps with a lower final drive? For the type of power that a few of us are running, longer gearing is the way to go.

 

3.5 ish would be awsome

 

DUH....IS F + No Mufflers + No Resonator =

I one of the guys in socal has Headers + no resonator + no mufflers...ZOMG

 

just bid on a is350 carrier on ebay...

 

^ i too have header... thinking of removing the resonator too.

 

Nice!! if you plan on doing the swap your self, you would need a 12mm allen wrench.

 

I own a Snap-On franchise, were not too short on tools around my place.

 

will the is350 diff fit on a '11 ISF?

 

i believe it fit but you will loose your LSD as the is350 doesnt come with LSD and the 08-09 isf have ELSD.

 

I suspect these would also fit - the GS430 has a 3.769, the LS600HL has a 3.916, and the AWD LS460 has a 3.133. They all use the same pinion bearings, so in all likelihood, they're all possible swaps if you're willing to have the gears installed. Not sure if the entire unit will bolt in with all of them, but on the GS, it definitely should be a bolt in process because the rear subframes are the same on GS and IS.

 

Does the GS430 have a elsd?

 

That resonator is the most important part of your exhaust system IMO. Remove it and it all goes to hell.

 

No, the IS250 uses a different differential design, it will not work without a subframe swap and custom driveshaft or adapter. It's smaller.

Yes, but you'd lose your Torsen LSD. If you were going to do it, I'd try to find a different Ring & Pinion set for your LSD, or get an IS350 differential and an aftermarket LSD for that case.

ELSD is electronic LSD, swapping in an IS350 LSD won't lose anything, as it's not actually related to the differential, it's just a part of the traction control system (independent of the differential itself).

Jeff