Rear end help!!

[bigmanjbmopar]

lol hey, trying to I.D. the rear end in this RR all I could find for casting numbers were on the carrier 2881488. just under that what looks like 148 or 748 between two cast flat head screws? real boiler plate cast lol.

only other numbers were a 3 just above the cast 288 and a side ways 9 on the upper drivers side near the housing.

Any ideas on what this is and holds? no tag on the bolts anywere some one must have left it off.

 

[bigmanjbmopar]

489 is what it works out to be as far as a carrier unit 8-3/4 but do not know the gears any hillbilly way to fond out what your gear ratio is with out taking the center section out and looking on the stamp?

 

[Meep-Meep]

489 is basically a 69 and later unit and a good one at that. If you have a sure grip you can jack the car up and mark the pinion and tire. Roll the tire one revolution and count how many times the pinion turns. Note: with a sure grip both wheels will turn at the same time and give you pretty accurate results, but if you have a one legger you must roll the car on the ground or find a way so both tires turn exactly at the same time. If you turn one tire with a one legger you won't get an accurate reading because the spider gears factor in.

 

[bigmanjbmopar]

Checked out and it is a posi got close to 3.5 turns around