What length should it be for a 5 wood?

I have a ENA 3W/Hybrid at 17deg loft and 43" length.
http://www.ebay.com/itm/Ena-Amazing-Flight-3W-17-CRANE-/271287865592

This is a senior club and I'm hitting it as long as (perhaps longer)my normal 15deg -3W

If I want make it to a 5W, what length should I cut it down to?
Currently is a C4 swing head.

I suspect, it's more complicated than just cutting the shaft.

Thanks for the advice.

based on my experimenting so far, yes it is as simple as cutting the shaft. From the butt so you might or might not need a new grip.

You can try cutting 0.5 to 0.75 inch. Or talk to the fitter about the distance you're hitting  with the current length and what you want to achieve with the new length.

Cheers.

Thanks Nam

The usual length for a 5w is 41". Every half inch different will yield 3 swing weight points in general, so if you cut 2", you will lose 12 swing weight if I am not wrong. One way to counter is to add weight into the hosel to achieve the desired swing weight.

Nutty thanks, you are right.
We need to counter balance on the head, when we cut the shaft.
Will pay BFG a visit soon.