Best flow? By far the Dynomax or Flowmaster Delta series. There are sites on the web from independant Pontiac racers (Tom and Floyd Hand, Jim Taylor) that have tested I believe 7 different mufflers with different engine setups..Most conclusive was the Dynomax.
Have not used Dynomax, but alot of people I talk to swear by them.
Flowmaster has a complete 2 1/2" dual system with H pipe and all needed parts for $260. I use their 50 series three chamber offset inlet/outlet and dropped my 1/4 times by 4 tenths with Flows.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
