I would recomend a T4 Turbo manifold. There are not as many choices for turbine wheel and exh housing sizes for the T3. Many more for a T4.
You will find the turbos will spool very easy on these inline six's, infact over spooling can be a problem.
Here is a site with Turbonetics Turbo Matrix. It is the second choice down.

http://www.treadstoneperformance.com/techinfo.phtml

The chart says 60-1 with a .68 housing

I think a T4 turbonetics 60-1 in P trim exh wheel with a .68-.84 housing will be very close.

Just this spring I dyno tested a 250 with a 60 size turbo and 5 PSI and it responded very well. 400 Hp should not be a problem, even with less than 10 PSI. Tom

Last edited by tlowe #1716; 09/05/10 10:49 AM.
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