Ok so whats the differences in like a T04S, T04R, and T04Z turbo? whats the difference with the letter at the end? I know itsa newb q so sorry, but someone tried to explain it to me and I couldnt understand them, hopefully someone else can explain it better....

 

Letters designate the different sized turbo's for the most part(if someone wants to explain exactly the hows and whys please go ahead, been there too many times.) Basically a TO4S is slightly smaller than the TO4R-Z which both are identical other than one Being BB(Z) and one not(R).