

I have extended 2 HF trailers and I used 2x2x3/16 wall and took it from the rear crossmember to 15" beyond the stock position.
On the first trailer I drilled and bolted all the crossmembers to the new center tube with grade #8 3/8" bolts. The other trailer I had welded.
It is worth the effort in added strength, peace of mind, and greatly improved road manners.