We did this to an old three speed truck transmission we ran in our modified sports class car. I don't know if it was worth the drag loss, but it did cause some issues because of my push truck errors at the end of the road. I caught the push bumper on the exit to the asphalt and almost set my airbags off. Our car needed about a 40mph push to put in gear and we would have been in trouble if Skip Hedrich hadn't helped us out with a push the next morning. If you are running in a very small engine class, it might be worth the headache, but in my opinion, I would keep first gear for a back up.