What's the difference between the two?
It seems that the problem, at least from what I can see with the guy in the link, is that he was using the Spectra 5 rotors which are just under 11" whereas the XG350 rotors are 12".
I looked up the Spectra 5 rotors and they are all about 275 mm which is about 10.8 inches whereas the XG350 rotors are 11.93 inches.
Are your rotors Spectra 5 or XG350?
And are the stock brake lines okay to use or should I try to get some stainless steel lines?
And will all calipers from 2002-2004 XG350 work?
Yes, exactly. I am going to do that with my XD2. Hopefully I will have everything within the next two weeks.
Okay, I think I figured it out. It looks like the BC140063 are for the 12" rotors and the BC140044 are for the 11" rotor.
The only way I can figure this is Ilan, you have the 44 model caliper and are using the Sonata rotors which are 11". The guy in the link you posted is using 11" Kia Spectra rotors with the 63 model and the pads are overhanging. So it seems like he needed the 12" rotor while you, Ilan, chose the right size. So since I have the 63 model, I will need 12" rotors. Does this sound right?
Okay, so it's now 3:07pm. I just got back from PYP where they had a 2003 XG350. Well, I checked out the calipers and here is the info on both models.
2002-2003 XG350
Caliper model: BC140044
Rotor diameter: 10.9 inches.
2004-2005 XG350
Caliper model: BC140063
Rotor diameter: 12 inches.
So, that should clear things up. So I have one caliper model BC140063 so I will be buying 12 inch rotors which is what I wanted to do in the first place. The only thing with doing the 12 inch is I will have to get them re-drilled. One of the companies who sells the rotors on ebay says they will re-drill for $25 a rotor. So that's what I'll do.
And here is a picture of the 44 model I saw today. It measured at 11 inches.
https://postimg.org/image/vxco2qyyf/