Anyone know how well a mast extension would work on a 460 75% carbon mast to use it on a 9.0 V8 which is recommended to run on a 490.
Thanks

It will most probably work, but may be not that well! 460s are a lot softer than 490s. You will find that when you rig, the sail will collapse more in the head, your sail will feel softer, you will lose upwind performance, but you should gain a bit off the wind.

bearing pugwashe's post in mind, it will also depend on your weight, if you are light a softer mast may even be a plus, but if you're heavy not so good!

Mattn, It will be terrible if the rig is a 2005 or 2006. I used to run a 490 radz mast in a 2005 V8 8.5 and it simply never felt right. I then bought a X6 490 and the rig is like a totally different feel. It twists off a lot more and handles like a dream when the wind picks. A 460 will handle like a dog. Get the right mast and you will be so happy you did. If money is an issue get an X3 until you can upgrade.

hi matt
depending on the age of the sail the luff on the 9.0m v8 is around 525 so on a 460 mast this will mean you need 650 mm of extension so with out a carbon extendo type extension this is just not going to work at all and even with a extendo it will bring your boom down the mast too far out of the zone they were designed for.
so any type of 490 is your best option also remember if the sail is an older shear tip type these sails were designed around a flex top mast not the constant curve masts we all use today
hope this helps cheers ian