Hello, is there any difference between Lexus GS and IS rear suspension. For example rear subframe part numbers are identical? And same with a lot of parts .

 

Look it up.

2IS/3GS has two subframes, depending on which diff body the particular model comes with.

By memory - IS250/GS300 has the small diff, IS220d/350/F & GS350/430/450h/460 all have "a" big diff (there's a couple of those but they are interchangeable, afaik).

Something noteworthy - it is easier to find a small diff torsen.

Don't take anything that I just wrote for granted, do your own research. Sorry.

Also, what are you trying to do?

 

I'm planning to replace my rear subframe because mainly of rust ,rear diff bushings are out, alignment bolts are seized . Planing to upgrade some bushings it will be easier and cheaper to buy all subframe from is 2-gen they are cheaper and better condition. Diff will be the same .

 

TLR - I'm running IS-F subframe bushings on mine, everything else other than diff bushings (haven't touched those yet) is strongflex (as soft as possible for the application) or OEM (all pillow ***** / ball joints). I dare not comment on whether it's harder or not (I have relatively new stock springs & shocks all around). As far as anybody I've ever driven is concerned (or at least what they've said when I asked) - the ride is on the "pleasantly soft" side. YMMV

Triple-check everything.