Go for it!
Love the TA-02 and just about every other Tamiya chassis out there. However, you just can't gear this car right to run a 25.5. You will need to be in the 4.0 FDR range. If you can talk your other racers into letting you run a Silver Can motor, I would give it a shot. Speed wise, it will be about the same as the cars running the 25.5. You will give up a bit in the corners but what the heck. If it doesn't work, all you have invested is in tires and a body. You can use those in a different chassis if you feel the TA-02 just doesn't cut the mustard. If you like Tamiya's, the TA-05 V2R is a good VTA car.
Bottom line: You aren't going to win with this chassis, but you can get out there and have fun.