Give Scott Smith a call, he knows which #s are best and what they're worth.
What I loved about the T-quad I had on a 406" SB street car was its throttle response & MPG; I didn't prioritize its WOT sound, but it was a bit of fun too.
That's an easy answer. If you ever find a 4000 series thats the nicer one... then the 6000 series. The 9000 series is considered tipically the "smogger era" but there is not a lot to change if you don't get connected any of the smog accesories. Carbs are about the same and tune up most the same. The "smogger era" is about misc parts around, not build into the carb (with minor exceptions).
Then you can tune up with metering rods and jets just as any other carb. The harder part is get the tune up parts for them.
