I'm glad you found the info on my website helpful, but I think you should recheck the math....adding up everything that has ANYTHING to do with the OS (except the prop and spinner, which you would likely use, surely???) I come up with 1335 and 1285, respectively with the Mac's pipe and the Aeroslave CF....what were you including that brought it to the 1500+ gram weight??? (I could have missed something you didn't)

I think the gasser is a great idea, and it should work very well....if you can keep the airframe light. And yes, moving the wing forward will be needed....I had a Hanson "Petrel" last summer, a one-of-a-kind that Dick Hanson designed at built, around the ZDZ 40 RE.....good design, great flyer, but I couldn't manage the throttle....and it was loud.

Keep us posted on your design!!