I have a #3 Ben Hogan 21 degree hybrid head and

I need some advice on what graphite shaft to install in it, and what trimming length to trim the shaft to.

Thanks in advance

You'll probably get a lot of replies like this...Hard to know without seeing your swing etc. You can go to many of the companies websites and they have a shaft fitter where they question you about your swing and recommend shafts based on that. Then it's up to you to decide if you're confident in going with what they recommend.

golfsmith.com also has a fitter that will recommend shafts after filling out a questionaire. And in case you didn't know...a high bend point promotes a low ball flight and low bend=high flight

Well, I'm not sure about hybrids, but some OEM irons have taper tip shafts.

That said, your hosel is probably .370" (so you're looking for an iron shaft), and probably taper. So, if it IS in fact tapered, that will seriously narrow your search (as there aren't that many tapered tip shafts).

You may want to contact the parent company, and get your hosel specs (Inside Diameter [ID], and whether it's taper or parallel).

I reshafted one of these, the shaft is a .355 taper tip, which really limits your choices. I went with an Aldila Gamer.