Go with the 12 x 12 Bennett Bolts. They will mount just under 10" up your 13 degree transom, see post #43 below link. We mounted a 27" bracket just above the top of the trim tab's bracket, about 3/8". No notching the bracket, worked perfect for a 25" shaft eTec G2. No thru bolt, just screws and 5200.
http://www.classicseacraft.com/commu...844#post258844
Oh yeah, the Bolts are very quick and responsive!!!