My neighbor just gave over his 90's gear, including a Mistral 7.5 Slalom race cam sail and a Mistral HCS board and a few beat up booms.
I'm looking for:
any of 490/500/520cm mast
Power Box head fins ~40cm
2 bolt base, mast extension

Changed title - I have a new 460 mast +ext - looking for 7-8.5 sail that doesn't need a 490+ mast.

Welcome, Brian! Are you sure the 7.5 doesn't take a 460 mast? What does the luff number on the sail say? I'll look around and do some research.

It asks for a 500m constant-curve mast. The RRD extension I have is 34cm max, so the luff would swallow a 460 by about 6cm, with no downhaul. Already tried and failed!
Anything between 490 and 520 would be useable IMO.

This is one of those sails probably made before the dawn of google. It's a Mistral Slalom Race Wing 7.5 m2, 500 luff, constant curve, 220 boom.

Brian, here's your other route. I'm assuming your 460 is standard diameter. And your base is US cup.

Chinook Extension Aluminum SDM US 48 cm. $75 - $95 new. You might be able to find one used.
www.worldwinds.net/chinook-extension-aluminum-sdm-us




Sidenote: Danny has his direct info on his mast post.

Thanks Reid - that's probably the best option. Shipping a 490+ mast from anywhere is silly expensive.

Tried rigging up this 7.5 cammer Saturday at Dempster with the 48cm extension on a new 460 mast - still way too short. It's missing a cam anyway.
There are some more modern 7+ freeride sails that will work with a 460 mast that will be much more efficient and lighter.