Well I made my decision to replace the rest of my exhaust system. :P
The sound quality difference alone that I experienced with replacement of my Firebird exhaust was far too sweet.
When I installed my headers, I went 3" up to the original resonator.
Now I will be replacing the resonator with a 3" SS performance res and going all the way to a Flowmaster Y splitter in 3". Then twin 2 1/2" into new polished stainless steel Magnaflow ultra low restriction muffs.
I chose Magnaflow over Flowmaster because of personal sound preference. Also because the Magnaflow is polished stainless and Flowmaster only makes aluminized units.
Yes I plan to reuse my stock cast aluminum tail trumpets.
I am sure this will allow me to run a 3.0" pulley....with 110 octane.
Parts are on order but I don't expect them to arrive until later next month.
It'* a March job and I will be sure to post pics.