Tire size

Im currently running 28X10.5-15s on the back of my car but I'm wondering if I should go with a 26" tall tire to pick up a little gear ratio?

030" 340
9.6:1 compression
Magnum heads unported
XE274H 230/236 .513"/.523" with 1.6 rocker 110lsa
650 double pumper
LD340 intake 1" tapered spacer.
1-5/8" headers 3" exhaust

727 10" converter
3.91s suregrip

3300 lbs with driver.

What do you think. I havent had the car to the track yet so I dont know what its going to run.