Best flowing metal cat for Sti v3 with mods?
 

I have an old 3'' Jap origine cat d/pipe for my hill climb Sti v3 which will be going back onto the car soon. Car can deliver 400+ bhp.
But, it is old and times have moved on.
Any ideads who makes the freest flowing cat, ie better than 200 grade?
I think Miltek do a 3'' 100 grade but only for the New Age cars.
Possibly the Graham Goode one is a 100 too? (but not 3'')

Graham.

Have I found a question none of you can answer?
Be a first if so!

Anyone?

Graham.