Hi Bill - I just finished putting my Lancair together a couple of months ago. I had a Saito 91 recently rebuilt sitting on the shelf, so I stuck it in there inverted. I also went with the Pitts muffler as well as a remote glow connector. It flys great with the 91 in it, and since the 91 and 100 are almost identical, I don't think you'll have any problems. I also went with a Sierra front strut, as you've probably already read about. That was the only problem I had as you can see from the pictures. There was not enough room to mount the Sierra strut on the firewall with the Pitts muffler in place. I solved that by installing the strut on the inside of the firewall. It flys great, climbs out very scale with more then enough power and is pretty fast as well. Ground handling with the front strut located where I put is great. It has plenty of suspension and have had no problem with it to date. If you'd like to look at a few other pictures of the engine mounted I have about 24 shots of it posted on my website, [link=http://groups.msn.com/PuttsRCHomePage/]Putts RC Home Page.[/link].

EDIT - I guess I'd also tell you that I haven't had the engine lock up due to fuel and being inverted. I have a Saito 150 in a AirTractor I built, also inverted, and have only had it hydro locked from fuel once in 3 years of flying it now. A few folks had warned me about it, but I guess maybe I've been lucky. Maybe someone else will chime in with any problems they have had along that line. I was also going to ask if you've done a search in the Scale Forum on the Lancair, quite a few threads there as well.

Hope this helps you in your decision and good luck.