Here is a link to a post I made about the phoenix models extra 300s. I took a bunch of photos and included them. I'm guessing that you wouldn't be able to mount the engine upright without cutting the cowl up pretty bad. My engine mounts came pre-installed. If you have any other ?'s I'd be happy to help.
[link=http://www.rcuniverse.com/forum/m_2565865/anchors_2660904/mpage_1/key_/anchor/tm.htm#2660904]my extra 300[/link]
Dan