Well Carl... all I can suggest is that you stick to something you're good at which could be... speaking BOLLOCKS! Rather than thinking or suggesting that you know ANYTHING about performance tuning.

You're right in thinking that the item you sold was in fact a T34 turbocharger. The item you are questioning us about is ALSO a T34 turbocharger. You see... the internals of the two units (bar yours having a 360-degree bearing) are EXACTLY the same. And yes... you can measure correctly (thank the days you spent measuring the dick on your forehead for that)... and yes the two units are different in size. Now... the reason behind this is SOLELY due to the difference in size between the turbone/compressor housings. The size of the housings on a turbocharger depicts two things (in simple terms for you)... the rated power output (amount rated flow achievable) and the amount of possible lag as well as the size of trim rotor used.
The bigger the housing, the bigger the trim rotor, the more power it is potentially capable of, but will suffer from more lag. The smaller the housing the less power capability, but less time taken to spool up.

Your turbocharger is EXACTLY the same as ours. Bar the size of the housings. Upon ordering our turbochargers we ask the customers which specific applications the turbocharger will be used with and it is down to that information that depicts the size of the housings needed/advised. For instance the APL525 (in question) is good for 350BHP. Where as our APL240 (also listed) is good for 300BHP, but suffers less lag due to to smaller sized housings and slightly different trim rotor. BOTH are T34 units, just simply different variations. We do a T34 turbocharger that is capable of 700BHP which would dwarf yours. Again, larger trim rotor, massive housings, great power potential but suffers from alot of lag.

I suggest you get your facts straight before being so abruptly rude, or at least look into things before thinking you know it all. Thank christ that you're not in my presence you arrogant twat. Don't want to be hearing from you again. Kyle - Hostyle Performance Tuning.