everyone pretty much covered it
nice car by the way
edited added; pretty damn good for only 451cid too
lower gears set in the trans
is a great idea
so is lower final gear ratio & looser converter
(
if you can taller tire, more roll out bigger footprint, if you go to a steeper gear/looser converter)
lighter rims/wheels & tires can help too
(draglites are pretty light for mass produce wheels)
lighter driveshaft etc. etc. etc.
weight reduction is great for many reasons
less weight more power to weight ratio
especially rotating mass
your car seems to be pretty light already
changing out some hardware for alum. or titanium hardware
albeit a PITA, sometimes a bit pricey too
Lexan windows ?
remove the window mech.s' etc.
carpeting ?
any areas you can remove or drill metal to reduce more weight
you can always add ballast to wear you need it afterwards
race at lower elevations, better air, hopefully better track too
more then one way to skin a cat
every little bit helps
try messing around with the numbers with a few calculators
below, before you spend a bunch of $$$
try
http://www.wallaceracing.com/Calculators.htm
you're pretty much at where you should be now,
car works well it seems
good luck