Hi Mate, i dont really know much about RB20 turbo, but the R33 turbo has the same flange as the RB20 which is t3...(as far as i know) i dont know what the r33 stock turbo is called, but its a t3 type with .ar50 on compressor, not sure about the exhaust housing (try searching the forum in regards to that) My stock turbo will be on sale once i get a t3 turbo replacement for this garrett, as i simply wants a bolt on job.ScarifieR32- My mech told me it will not be too laggy, it will boost from 3500rpm or 4000rpm from usually approx 2200 rpm(from my stock turbo) i would put this in my r33 if i have the extra money to buy manifold, wastegate,vband etc..but i dont