Doc GARF.org is a great site for plans, but if you build one go ahead and add a few extra 2x4's for support. When I build them I way over build them.LOL But you would acctually be supprised how much weight 1 2x4 can hold. I looked it up once and can't remember now but think it was like 600 lbs per inch, so with all the weight distributed then your actually pretty good. I built the one for my 125 and was alittle scared when I set it up, however, it did great.