I am planning to build a single slope carport. I will use three 12ft 4x4s on one side, and three 10ft 4x4s on the other. For support beams, I will run two 10ft 2x6s on each side for a total length of 20ft and then use 12ft 2x4s every two feet for roofing rafters. I'm just not sure how to connect the two 10ft 2x6s at the point where they meet the 4x4 post. I don't think 2 inches of overlap is enough to use carriage bolts. I appreciate any help!