Here’s my latest progress. I got some unistructs from Lowe’s, along with the 90 degree brackets.
The biggest expense is the u bolts, about $12 a piece. The rest of the stuff are quite cheap.
One problem is the sidewalls of the trailer aren’t completely uniform, so the front and back brackets are not level with each other. But I think I can fix that by chiseling the bottom of the bunk where it attaches to one of the brackets.
I bought 2 pieces of six foot long 2x6s. Someone with the same boat told me that he was using 2x4 but the boat would slide off to the side.
I’ll leave the motor inside my SUV so probably fishtailing won’t be a problem. Also the trailer has a long 3x3 tongue, so the tongue weight isn’t too light.