I bored out my 91 mr2 turbo inlet, which was given to me by a friend, with a dremel. If you have the 91 inlet thats what id do. No reason to waste money where you dont have to. I also doubt 10hp gains from just the 93 inlet itself unless you are using 2.5" ic piping causing the inlet to become a restriction. If you are using 2" or 2.25" ic piping I dont see how the inlet can become a restriction because even the 91 inlet has about a 2.25" opening.
John 92 st185