Here's the scoop.
When I first bought this car it had a 305 and stock TPI. I did the usual mods which included shorty headers, a 3" flowmaster cat back and a 30 series muffler. Now the 305 is long gone and in it's place is a somewhat built 350 (see sig for mods). I've improved the exhaust along the way with LT headers and decent y-pipe and no cat, however the 30 series flowmaster muffler remains.
I'm sure the vehicle is capable of better numbers that it shows. Dynoed with less than 300rwhp and runs 12.7's at 105 mph. From racing and research I've narrowed it down to a couple of things the most obvious of which is the crippling exhaust. Namely the muffler. For the record, the other problem is not having a CAI but that's another thread.
It's well documented that for a muffler not to pose a restriction it has to provide about 2.2cfm of flow per HP the engine is capable of producing. That 30 series probably flows about 250 cfm!
See my point?
What I'd like to know is what others are using for a SINGLE muffler and with what results.
Et's or dyno numbers would be appreciated.