[Jsandore92]

I have a e92 335i manual trans, I plan on swapping the m3 diff, half shafts and drive shafts into the car. My question is if I should use m3 control arms or something aftermarket like ground control or rogue engineering. Also if anybody has any experience with the Godspeed spherical arms, would like to know more about them since they are much cheaper. Thanks.

[DialedIn]

I would just reuse the old control arms and put polyurethane bushings everywhere.

I'm not sure the two upper m3-arms have better bushings than the non-Ms.

Note that the M3 rear toe-arms are significantly shorter than the non-M and cannot be used.

[mpathic]

The "I'm sure that" claim should be verified with the factory part number, where you will find that the bushings, ball joints, and arm lengths on the rear are the same between the M3 aluminum and non-M stamped steel arms. Statements like your's are how "read it on the internet" fallacies get started.
Only difference might be a few pound weight savings, at most. But if you dink a curb, much more and more expensive damage than just replacing a cheap steel arm.

Go with oe factory steel arms on rear (Lemforder or Meyle Germany brands ONLY), with new Whiteline bushings where available if you want to splurge for not needing to ever replace them again but not any noticeable suspension improvement vs new factory rubber bushings, or where not, press new OE rubber bushing into your existing arms, replace upper middle inner arm's balljoint too.
New arms come with new bushings and/or ball joints, more expensive but saves a TON of headaches and cursing and maybe a trip to the machine shop anyway. On the front suspension, install new bushings or the M3 arms that come with new bushings in them. At lease, use the M3 front thrust bushing instead of the factory non-M oil filled bushing that's guaranteed to break and leak oil out within 50k miles or less.
Swaybars: //M3 Convertible 28F and 23.6 rear swaybars, with //M3 style bushings, not the factory non-M bushings. M swaybar bushings are two steel shells, smaller and larger diameter, with _very _dense rubber molded in between. Do not use aftermarket urethane swaybar bushings. One look at the factory M bushing, both before and after installation, will convince you that this is a superior bushing screaming of German over-engineering that's well worth using vs anything else available. If replacing only 1 sway bar, replace the rear, and still put the M swaybar bushings on your stock front 26.5mm swaybar. That makes a HUGE difference in cornering and stability vs the puny 13.5 mm non-M swaybar these other E90 come with.

[Jsandore92]

I like the adjustability of aftermarket arms. I'm on bc racing coilovers. I want to drive the car on the street and do autocross and track days.

[DialedIn]

Originally Posted by mpathic

The "I'm sure that" claim should be verified with the factory part number, where you will find that the bushings, ball joints, and arm lengths on the rear are the same between the M3 aluminum and non-M stamped steel arms. Statements like your's are how "read it on the internet" fallacies get started.
Only difference might be a few pound weight savings, at most. But if you dink a curb, much more and more expensive damage than just replacing a cheap steel arm.

The M3-toe arms are not the same... found that out the hard way myself.

Originally Posted by Jsandore92

I like the adjustability of aftermarket arms. I'm on bc racing coilovers. I want to drive the car on the street and do autocross and track days.

If you go with polyurethane bushings your rear camber adjustment will be significantly limited. I get a maximum of -1'50° in the rear. Adding an adjustable aftermarket camber arm on the top will allow you to set the camber to factory -2'00° and higher.

Originally Posted by DialedIn

If you go with polyurethane bushings your rear camber adjustment will be significantly limited. I get a maximum of -1'50° in the rear. Adding an adjustable aftermarket camber arm on the top will allow you to set the camber to factory -2'00° and higher.

Manzo arms a good/cheap upgrade and come with solid rubber bushings.