[V8 Bob]

The '49-'51 Fords are the same overall length, but differ in mounting as tubman stated.



The '49-'50 and early '51 Mercs are completely different with '32-'48 round pattern cases, but regular production '51 Mercs are the exact same as the 4-bolt '51 Fords except for shift levers. The convertible OD tail housings may be different because of relay locations between F/M.



The '52-up Fords/Mercs will work but overall length may be different than '51, requiring drive shaft mods. The '49-'51 side covers do have an extra boss that supports the brake and clutch pedals and should be interchangeable with some later B/W trannys, but

I would contact VanPelt for more info on later year compatibility.