So educate me on a "gear swap" please....

[lenniesdad]

Hello. I got a lovely 71 HiBoy 4X4 250 with a 360 and 4spd. I am running stock 4.10's with modest tires, 305/70R16 and I like them so I'm sticking with those but as you can imagine her legs are short. I want to go with a taller gear set for better highway speeds. I have entertained the NP tranny idea, ranger torque splitter, but the older I get the less interested I am in cabbaging my truck with a bunch of anti-stock modifications. It seems the first thing to do to leave the truck as reliably intact is to swap differential gears, however I am woefully uneducated on what it takes to swap differential gears. I am getting the sense that this is a very touchy procedure that a mechanic should do. Is this correct? Is there a simple way to pull a set of 3.73's or something from a junker and just install them? I am pretty mechanically inclined but I've never dug into differentials before. Some explaination or a "thread" maybe? Thanks guys.

[averagef250]

305/70 is a 33X12.50. 3.73's would be a great match with an FE. No overdrive needed. If your engines gruntier than stock 3.55's would work too.

Iirc you can reuse the rear D60 carrier, but the D44 front will need a different carrier for 3.73 and lower. Gear swaps aren't usually a job for a mechanic, but a gear shop or atleast a mechanic shop that's a hell of a lot higher up the food chain than brake pads and timing belts. There's a simple process and a couple of specialty tools required (like a clamshell bearing puller), but you can get by with making setup bearings if you plan it carefully and aren't shooting for doing regular diff work.