[updated:LAST EDITED ON 18-Jul-02 AT 02:53 AM (EST)]i need to find out whether my ranchero has 28-spline axles or 31-spline.
it's a '75, came with 351W and FMX tranny. rear is a 9" with some kind of posi (trac-loc i think) and 3.89 gears. i think the gears & posi were some kind of optional "towing ready" package - but not sure since it didn't come with a hitch. the rear brakes are 10"x2.5" or something like that. factory wheels were 14".
reason i'm asking is that there's a 9" rear for sale from a '75 lincoln, complete with rear disc setup. it reportedly has a 4-link rear suspension, so i'm thinking it will swap right in - but the only way i'd be interested is if i can swap in my complete center chunk (gears & posi). i've heard that the lincoln housing is wider, AND the axles stick out farther - which means i can't just swap my axles into the linc housing along with the center chunk - i'd have to use the linc axles, which i think are 28-spline. so if mine is 28-spline, then it should work. but if mine is 31, then it won't work. wheel offset isn't a consideration, since i'll be getting different wheels anyway.
does anyone know about this swap?
i know it's easy to pull an axle and count the splines, but the ranchero is in storage across town and not in an easy position to jack up right now. does anybody know - 28 or 31?
I would bet that your Ranchero's axles were of the 28 spline variety. They are decently strong, and since you are running a 351w you shouldn't have a problem. The '75 Lincoln disc brake rear axle assembly has 5 on 5 inch bolt pattern while your Ranchero should have a 5 on 4.5 inch bolt pattern. Re-drilling the axles and hubs will correct this easily. Hopefully the rear axle is from a Lincoln Mark IV and not a Continental.