My search for information has yielded this:
My 155 genoa has a luff length of 31.1-ft.
I have heard of other people having S2 7.9 head sail luff lengths greater than this... as great as 31.6-ft.
The class max allowable on the pin to pin on the fore stay is 31'-8". Most people including myself are at the upper range.
31'-7" or greater.
roller furling?
Moderators: sderby, Tim Bosma, Tom Elsen
Re: roller furling?
Now you're talkin'! 
Re: roller furling?
FYI on cutting down a load path string sail......
here is some dialouge I recieved from the North Sail service dept. in San Diego CA regarding some questions I had posed to them about cutting down a 155 North 3DL genoa....
>>>>>>
"Yes- technically all the load yarns originate and terminate corner to corner, and re fairing will cut some of those yarns. However, we always add a length of 4" PSA kevlar tape, or a heavier weight 6" strip of kevlar sail cloth to make up for the "lost" yarns. It is something we commonly do in cutting down sails for furlers.
The most highly loaded yarns are in the leech, so we try to avoid re cutting there. The foot sees much less load, and could be better for re cutting. The length that we shorten the sail will determine where the re cut needs to be.
Andy
from.....
andy@service.northsails.com
here is some dialouge I recieved from the North Sail service dept. in San Diego CA regarding some questions I had posed to them about cutting down a 155 North 3DL genoa....
>>>>>>
"Yes- technically all the load yarns originate and terminate corner to corner, and re fairing will cut some of those yarns. However, we always add a length of 4" PSA kevlar tape, or a heavier weight 6" strip of kevlar sail cloth to make up for the "lost" yarns. It is something we commonly do in cutting down sails for furlers.
The most highly loaded yarns are in the leech, so we try to avoid re cutting there. The foot sees much less load, and could be better for re cutting. The length that we shorten the sail will determine where the re cut needs to be.
Andy
from.....
andy@service.northsails.com
Re: roller furling?
Doing as he says still doesn't make it a "load path" sail again. It either is or isn't. Will it work for your purposes? Probably, if you're not worried about great shape and longevity...................................