Riveting my floor plans - using lots of bits

[hillcountryflt]

Jeez. A friend and I began putting in new floor plans in my rustbucket, my 71 flareside. Driver's side pretty rusty, passenger side not so bad. While I was originally going to cut them out, he suggested just overlaying the new over the old. The guy has rebuilt many a car and as he said, "if we were going to do a restore for shows we could be cutting out the old, but this is a driver, so leave them in. Lot faster to install and once properly riveted will be as strong if not stronger than before."
That being our course of action, we have now gone through a potload of 1/8 drill bits. Some last a while (4-6 holes) others not even a hole. I am going to be looking around and see if I can find any "shorty" drill bits.