Why?
Seriously, Continental and RV's is an odd if not totally rare combo. You would be pretty much on your own. Even Van, who dabbled in the idea of an IO360 for RV-10 dropped that.
To answer your question I actually did see a RV-7 on eBay about a month or two ago, so one does exist to my great surprise. I would point out that this Continental powered RV-7 had NO time or low time (the Guy was about to or just flew it once recently?) which is odd. People don't usually sell a completed plane and not fly it at least thru phase I (40 hours). I should say not common for RV's. Some times people scare them self and sell their project with no or low times, but as I say that's not the case with RV's.
Sorry I'm no help, but advice is free and worth every penny you paid for it.
My suggestion is stay away from the TCM for you RV project. The Lyc and RV are a matched set in every way. Any super big mod (like new engine mounts) will be a nightmare and take way more time to build. Also all the accessories, exhaust, airbox and on and on are available from several sources. A custom deal like a TCM powered RV is a do it all your self. The aforementioned eBay RV7 with the Continental showed the cowl needed some not so trivial mods to make it work. Frankly it looked real rough. I guess that is why the asking "Buy Now" price and bids where so low.
Good Luck, but stick to the plans, keep it light, simple and you can't go wrong or at least its easier to go right and save countless hours.
