The stainless bracket that racex has is the same bracket as I have. It weighs 130# and then a 150 outboard 390# = 520# off the back.
If done right it will last a life time!! I have had no issues with mine in the 3 seasons that I have used it!!
But my transom was good and I filled the hole solid!! And just to be sure I had a bracket made for the inside that would spread the weight across the whole transom, It is made of 1/2 X 3" flat stock with 4 coats of ZRC to help with the rust, Haven't seen any rust yet!! ;D
And I never trailer with out a transom saver!!