James
i have these lurking in my garage
Dimensions of the tubes are 1 1/4" I.D, 2" O.D
Length of pipe is 6" no bottom to them so you can fix them half way up yer boat and the rod butt will be on the ground.
Ally bar which they are attached to is 12" long by 1.5" deep pre-drilled and all edges have been reemed
i have two of these if you are interested??
i know you are looking for more holders but??
let me know, and we can come to some arrangement.
Macharpool
http://s558.photobucket.com/albums/ss27/macharpool/let me know if the pics come through