i want to put on 15" drag radials for the track like nitto or bfgood
225/55/15

how would this affect my gearing?
shorter or taller? and why

 

I've been trying to do the same thing for awhile now but theres not too many light weight rims made in 15' and 4x114.3. Have any ideas what rims you would use? So far the best rims that I've found are rota slipstreams. They aren't too many shops that carry them in 4x114.3 but they can be found. They weigh like 11 pounds each.
As far as gearing getting affected I don't see why it would. The gearing on your tranny isn't going to change just cause you use different tires.
What is going to get affected is your axles and clutch. Lots of strain gets put in the axles when you use slicks and you can very easliy break one. And obviously your 60 foot time is going to be affected.
f0de use to run nitto 555r's on his cl on the stock rims and he broke a couple axles in the process.

 

i'm having a hard time finding rims too
summit has some for cheap but they have to order 15x7.5"
i was going to get those lightweight black steel, they weigh 13 i think and are 70 a piece if i remember right

i'm pretty sure that changing tire size will affect gearing
i know it changes the speedometer readings