BMW E36 Compact rear trailing arm size compared to Z3
 

hi
basically i am somewhat confused regarding the rear trailing arm sizes that are available , I have a rally 36 compact but I am unsure of what the original builder used , so just asking if there are any tell tale signs as to the diffrence in the trailing arms , I seem to see that Z4 ones have a reinforcing bar across the "V" but are they wider in the hub or elsewhere?
thanks in advance