I have not done that plane but have converted a 72" QQ Yak over to a DLE30. I could not shorten the firewall and still get the cowl to mount. So I just made a hole in the firewall for the carb to stick into. It made it difficult to hook up linkage and fuel lines. But once it was done it was a great combo. You will have prop clearance issues with that plane. So plan on some taller gear or a rebend of the stock gear. Balance was not an issue for mine. I did just use one battery for everything and use an IBEC. My plane had a Saito 1.80 and the DLE30 is not much heavier and far more powerfull.
David