Does anyone know the specs and/or a supplier for the longer studs to attach a wingplate to a #3,4,5 I believe they are circa 5 3/8" and each drive would require 4. The next question is best method of removal! Thanks Dave

I just mounted a wing plate. I bought stainless bolts with the course threads ,I think they were 5/16ths. They were 4" bolts but only threaded about 1 to 1 1/2". Cut the bolt to the length I needed and threaded with the fine threads of the mounting bolts.

I hate the "cut to fit" idea. Who did Mayfair / Marine Machine get their drive studs from? (since they don't seem to be able to get them either)

Try Latham marine. They have all different sizes and styles.

Mcmaster Carr has a good selection of stainless studs. http://www.mcmaster.com/#standard-threaded-rods/=or3bhe