stock floor body drop tranny tunnel

ok guys, i'm putting the cab back on the new frame for my truck and i was wanting to know if any of you guys have done a 2 3/4 stock floor on a mazda (89-b2200 standard cab)if you have to raise the tranny tunnel up and by how much? i don't have the option of lowering the motor and tranny because the frame is so short now, any help is greatly appreciated!