Can i use a smaller bit to put the pilot hole first ?
Not a chance in hell because you can not center it perfectly in the hole .
If you vary from my instructions in any way at all, you may end up with a problem, but as i said, its you car and you will know how to change the cam on your own next time .
If you drill the hole in the wrong place, you will be buying another $300.00 distributor which is not a big deal because they now have plenty in stock .
Cutting corners is exactly why your gears blew up in the first place so i don't understand the logic of wanting to do the same thing they did .