I think you will have more choices (w/a T4 turbo) for Ebay turbos to get the size you would need.
As I stated in previous post,seems most T3/T4 turbos on Ebay are too small & are mostly for 4 cyl engines.

Companies like Turbonetics, Garrett,Precision turbo, Exile, etc, can make you a correctly sized T3/T4 turbo, but they will cost more & will be a much better turbo.

Also, w/a T4 turbo, you can get an "on center" turbine housing to give you a little more room away from your steering shaft.
PG 22
http://turboneticsinc.com/forum/turbos/TN_2011_CAT_MED.pdf
http://cgi.ebay.com/ebaymotors/Turboneti...sQ5fAccessories

http://cgi.ebay.com/ebaymotors/GODSPEED-...sQ5fAccessories

*NOTE: The "on center" housings are not as efficient.


MBHD

12 port SDS EFI