Originally Posted by javyLSU

Ok, so thanks to 2 of our best vendors, Carson Toyota (www.L-Tunedparts.com), Sewell Lexus (www.sewellpartsonline.com), and a few Club Lexus members I can now verify "bolt-on" fitment of the IS-F BBK onto the ISx50. There are, however, some details that need to be known:

1) As previously mentioned, the front hubs from the IS-F are needed for this to work. I've received confirmation from Sewell that they are including the front two IS-F hubs in the IS-F Brembo BBK they're offering, and have changed the product listing to reflect that. That's an INCREDIBLE offer, considering that the MSRP for the front pair of hubs is $630.58. Again, just an outstanding offer - kudos to Darrel and the rest of the folks at Sewell.

2) Because you must use the hubs from the IS-F (which are 1/2" wider each), the front track of your car will be widened by one inch, effectively changing your vehicle's offset on the front axle. This is big news for those of you running aggressive offsets in the front. For example - if you're running a +36 wheel in the front, installing the IS-F Brembo's will make your front wheels fit like a +23 wheel. Again, caveat emptor.

A few notes about the hubs:
The hubs (and the ABS speed sensors that are installed in the center) are SIDE SPECIFIC, marked with an individual part number and an 'R' or an 'L' to avoid installing them in reverse. They are dimensionally identical, so be careful when installing them. If you install the hubs or sensors in reverse, your vehicle's ABS computer will trigger a DTC P0500 (speed signal malfunction) as soon as you reach 50 mph, and you'll get a 'check VSC' warning indicator on your dashboard. Once you have this light you must go to the dealer to have them reset the DTC.

To my knowledge, the AWD has not been tested for fitment. I can see the AWD front hubs carry a different part number (and a slightly lower price), but I have no direct knowledge if you can install the IS-F hub onto an AWD 2IS. Caveat emptor.

If anyone has any question on this don't hesitate to ask. Thanks again to Luis, Steve, and Caesar at Carson Toyota; Darrel Diller at Sewell Lexus, and CL members Joe Z, Lance (lobuxracer), and Ferry (B_390_LU).

Javier