Have done the research but defer to definitive expertise. The rear torque tube axle in my truck has the carrier stamped with the numbers 3657339. Looking in the master parts catalog (section 5.504 carrier assembly, differential, w/propeller shaft tube), it shows 2 carriers with the same number, one used 41-46 and one in 47. The difference i believe is the length of the torque tube. 41-46 listed as 58 1/2" and 47 listed as 62 1/2". Measuring from the end of the yoke on the torque tube to the front lip of the carrier housing I get 62". Am I measuring the tube in the correct locations? Is 62" close enough to call the rear axle a 47. Truck is titled as a 46, has locking passenger door like a 41, so who knows whats original and whats been scabbed together.

Reason for id is that I am installing the 3.55 ring and pinion gear set. Instructions state that a 54 1/2 ton needs the correct carrier for this conversion, spool casting #3652336-40-53, 1/2 ton trucks.

Clearly the axle is 41-46 or 47. but what are they referring to as a spool casting, and is my axle compatible with this conversion?

As always thanks for any information and advice.

Ed

"it's only old if you can't find a use for it; otherwise it's cool and i'll use it."