For shipping, I would recommend MustangTuning
http://www.mustangtuning.com/fopege3ra1.html
Free shipping and fairly low price ($179.99)
Ford wants $199.99 for them. Also, their website lists only M-4209-F373N as a part number for the gears. This is the same one I have in my car now. It says it replaces M-4209-F373. The other part number with an "M" (M-4209-F373M) is listed as gears for a 7.5 rear.
Anyway, FWIW, the "N" in that part number indicates a new CNC process for cutting the gears which apparently produces stronger gears, so I'd say you're pretty safe with the "N" set.
http://www.mustangtuning.com/fopege3ra1.html
Free shipping and fairly low price ($179.99)
Ford wants $199.99 for them. Also, their website lists only M-4209-F373N as a part number for the gears. This is the same one I have in my car now. It says it replaces M-4209-F373. The other part number with an "M" (M-4209-F373M) is listed as gears for a 7.5 rear.
Anyway, FWIW, the "N" in that part number indicates a new CNC process for cutting the gears which apparently produces stronger gears, so I'd say you're pretty safe with the "N" set.
"New manufacturing technology utilizing a Face Hob Process which features a single pass pinion tooth machining operation compared to a conventional three pass process for machining. CNC cut and lapped gear teeth. Higher strength and better quality gears are produced with the Face Hob Process. NOTE: These new gears look a little different, the gear teeth are cut on a different angle and the ring gear has a bevel on the back of the gear."