Will an early(79-95) solid axle 8" 3rd fit the rear of a 98 4runner? Are all 8" thirds the same regardless of year and whether they came out of the front or back ?

 

yes it will fit the 4runner, as long as that 98 4runner did not have an e-locker third.

The non e-locked tacomas had 8.4 diffs

 

Right on. E-locked axles have a slightly different opening, but a regular 8" third will fit just fine. Just be sure to check the gearing. Most stock early 3rds are 4.10 because of the manual trans; I THINK most of the 3rd gen 4Runners are auto and have 4.30s.

 

There are two types of rear 3rds they are named 4cyl and V6. They V6 have thicker ring gears and larger bearings, this is the one you want.

Also E-Locker rear ends use V6/Turbo Gears and there is no such a thing as a 8.4" Toyota Rear end. The supposed "8.4" runs a 8" ring gear.

 

some are 3.90s Most are 4.10s and the ones with e-lockers are 4.30s