He he he he... you're right. We werent arguing. Those company's sell those kits as is. The only company that offers option is MAXREV. However, their option is only on the trim sizes such as a T3T04e or T3T04b.
Taken from:
http://www.hstuners.com/forums/showt...=&threadid=185
A/R -A/R means area/radius. It is a formula to determine the size of the compressor and its turbine-housing configuration. Sounds like a lot but to make it simple, the smaller the A/R the faster your spool up time. But the downside is that the top end will suffer and choke off. If you have a large A/R you will be able to flow more air but you will experience a longer spool up time and poor response also known as turbo lag.
peace out cashiz