Your times are just like mine were with just lid/exhaust. I was running 13.5 @ 102 all day long, regardless of how I drove it..
Biggest gain was with the converter. Cut my 60's from 2.0-2.1 to 1.72s (and still falling). Only downside is, it eats gas revving to 2500-3000rpm in city driving. Next big gain was headers y-pipe w/ cats.. traps went from 102 to 108.. picked off a couple tenths there as well.