Willy, are You sure? I have never heard of a taller gear for a 9" than a 2:47.
Bob
p.s. I am sending You a p.m. on another matter...........
Bob - I came across this and wondered the same...I know that there was also a 9.5" rear axle that went into big Lincolns and Mercurys - as well as Ford Trucks in the 70s and maybe more recently.....Sparky turned me on to this....The Lincolns for sure and maybe some of the bigger engine Mercs had as an option a 2.29 gear ratio....Very few of he parts for these 9.5 gear ratios can be interchanged with 9" diffs...The whole center section has to be used and they came only with 31 spline axles....they do bolt into a 9" housing but the flange has to be relieved some both top and bottom to clear the ring gear....
What I do know about some of these "oddball" gear ratios is that Richmond Gear and others made many special ratios for 9" Ford diffs - Now - if only I could find some fill in the "huge" ratio gap between 2.75 -1 and 2.50 - 1 - although I DID find a super rare set of 2.69 - 1 gears for a Ford 9" rear end......