With a 4-speed and 4.30 gears, you should be able to run a 27"-28" tire without a problem. I run 4.10 gears with 28-9X15 MT ET Drags(which are actually 27.3" tall) and a 727 auto trans with LUPO 5000 stall. I've ran my old 340 1/8th mile and 1/4, it works great either way.
