Headstay length?

[Atavist]

As I mentioned in another post my OLD seafurl system is having chronic halyard wrap issues and I no longer trust it or the headstay... the cheapest way to go for me at the moment is to just have the sails converted to hank on and replace the system with an old fashioned wire stay... I just went up the mast and tried to measure the eye to eye distance from the forward chain plate to the mast-head... my measurement was 42' 3" ... does this sound right to any of you who have replaced your headstay?  I am planning to do this myself (once again cost cutting) and want to make sure I get the stay made to the right length the first time..

thanks,
J