When I did mine, I re-used the same skid bolts that came with the drop. But depends on the bolts - I was lucky, mine were threaded all the way to the head.
As always, I like to advise people the 'through-bolt' on the stock motor mounts needs a 18mm wrench/socket. It's an unusual size and most tool kits don't have it.
It's a real pain to go get one half way through the installation.