mine were the narrow track. i will check part number for you tomorrow, but johnh said they were 924S and they did have a 951 part number (since this was a shared part). so you are looking at 1.5-2" wider.
no sure if you are just wanting to go 100mm on the inside, but you can go with the 33-spline (at least i think it was, do a search i have it on here somewhere) 944 axles which allow 100mm on the outside, but keep the 90mm on the inside. of course, if that was just your rationalization for going nuts...disregard.
