On the last trailer I rebuilt I had some beams given to me from under a bridge that was being replace near my house that were 6x14" salt treated. I cut them down about 8" tall and then cut them on an angle to match the seacraft 20's hull panel. I made some brackets from 4" flat bar that clap on so there were no holes to drill in the trailer and that also allow them to be adjusted. They work well and will last for ever. I have seen people also use 2 2x8"s screwed together and stood on end and they worked well also but an oak beam is better if you can find one at a reasonable price.
