I welded bracket for the seawater strainer (perko 493 #6) out of 1/8 or 5/32 SS angle I had lying around, then bolted it to a glassed-in block of plywood.
Location is a few inches forward of the V-Drive
the two bolts (1/4 x 20) holding the strainer are tapped/threaded into the upper part of the bracket, then welded in place so they don't move.
Base of bracket has three holes for hold-down bolts.
Base if made of 3/4" teak plywood and glassed into bilge.
I set the bolts in the plywood with epoxy before I glassed the thing to the hull.
Setting bolts in base plywood.
Drilled a 1 1/4" hole half way up from underside of plywood.
Drilled 1" hole down from top of plywood.
Welded scrap SS to the head of bolt so it would have better grip on the epoxy.
I glassed the plywood with bolts to the hull. Once resin cured, I ran the die down each bolt to clean the threads and hung the strainer on the bracket.
Below are three pictures.
http://bodylens.com/p69/SSbracket/Strainer-lookingafttoport.jpg
http://bodylens.com/p69/SSbracket/Strainer-lookingafttostbd.jpg
http://bodylens.com/p69/SSbracket/Strainer-lookingtoport.jpg
X-section drawing of the plywood base plate with bolt
http://bodylens.com/p69/SSbracket/mountbracketplate.JPG