What headers?

[thunderbolt]

Carol Shelby thought they were so crappy he put them on all his gt350's. Seriously, what do you want to do. Long tubes are generally good for high rpm race applications. Tri Y's are supposed to be very good on the street, giving decent top end gains,(not as good as 4 into 1 long tubes) and much better torque numbers than 4 into 1 long tubes in the lower RPM bands.
The questions I would ask, are what rpm range is your engine going to live in. What are your primary tube sizes and what about the rest of your exhaust. From you sig, your exhaust looks like a good street set up to me, I would run it.