Will have more guides on an overhead rod to keep the line from touching the blank while loaded up. Quality rods will be built on the blanks backbone which will be different between oh and spin. First guide will generally be larger on a spin rod to counter the larger coils of line off a spin reel while you are casting.

 to put it simple. more guides on o/h and guids on back bone where as spin guides are under back bone.

if your planning to build an o/head rod or buy one, test where the backbone is just put a slight bend in the rod and roll it around and you will feel it. i have tested some rods off shelves where the backbone is in the wrong place on the rod. when i told the owner of the tackle shop, he said it must be right as thats how we buy our gear and you wouldnt have a clue. never went back there 

Thanks guys, never knew about the backbone in a rod, just shows, never too old to learn. Will have to have a look at my rods now, I am sure I have a few matched to the wrong reel.

Cheers

Old Banga!

Don't get too excited about the backbone.

Its a construction fault from wrapping, and wrapping is done so well these days its not usualy very pronounced.

Next, unless the rod is built by a rodmaker, not some shed in thailand or china, it won;t be built on the backbone anyway,