Here is a heavy tail dragger conversion:

http://www.rcuniverse.com/forum/m_19...tm.htm#1963113

I don't know the weight of mine, but it is heavier than normal and flies fine with an old Surpass 48 (though not at all over powered). An LT-40 isn't going to be terribly adversely affected by the extra wieght. It will fly a bit faster. If it weighs ~25% more than normal then it will fly about ~10% faster than normal. You'll need more power to fly it comfortably. Keeping in mind that a light one will fly just fine with an LA40, that still doesn't amount to much power.