Sounds like your setup is pretty good, but it's clearly not a highway cruiser.
T350 tranny is a good choice, but it is just a 3-spd with a 1:1 final ratio - 9/10ths turbine to impeller loss.
You didn't mention your rear tire diameter, but if you are running small tires with 4.11 gears, that would be a higher RPM setup.
Are you trying to go faster, or save fuel? ( Or both? )
If you don't mind giving up some acceleration force, you could just run 3.55 or 3.73 rear gears.
Using your rear tire diameter, calculate the speed and RPM's you want, and choose the corresponding gearset. A gear-swap is cheaper and easier than trying to do a tranny swap.
If you want to keep your 4.11's... think about a 700r4 and some taller tires.
Since it's not a dedicated drag car, I would do the gears.
Here is a link to the calculator:
RICHMOND Street Performance Calculator