Rearend bar codes?

I drive an 05' 4dr pre runner with apparently the a base model 2wd differential that was installed out A lack of finding original parts. I now have two options. I'm able to purchase iether the limited slip diff to install inside this current housing, but will it fit? My other option is buying the whole rearend off a 2008 pre runner. All the information I can find on both enemy current housing and the new complete differential is bar codes and what I'm assuming are some serial numbers on these housings. My question to you guys is do these bar codes decipher what I'm trying to learn?

 

Welcome to TW! I know the 2nd Gen Tacomas have 2 different sizes of differentials. I could be wrong but I think the 2WD and 4WD with rear locker have the 8" diff, and the 4WD without locker has the 8.5". I'm sure someone will chime in and correct me if I'm wrong.

 

Amazing what google can find you. Not sure if these are limited to certain years or gens but proof that a little searching will find you what you are looking for.

TACOMA DIFFERENTIAL CODES
First digit:
A = 7.5" ring gear
B = 8" ring gear
Next two digits: 01 = 3:42
02 = 3:58
03 = 4:10
04 = 4:56
05 = 3:15
06 = 3:91
Last digit:
A = 2 Pinion, Open
B = 4 Pinion, Open
C = 2 Pinion OEM Limited Slip

Using the above codes would result in the following axle codes:
B01A 3.42 2 pinion open 7.5" ring gear
B01B 3.42 4 pinion open 8" ring gear
B01C 3.42 2 pinion posi (OEM limited slip)

B02A 3.58 2 pinion open 7.5" ring gear
B02B 3.58 4 pinion open 8" ring gear
B02C 3.58 2 pinion posi

BO3A 4.10 2 pinion open 7.5" ring gear
BO3B 4.10 4 pinion open 8" ring gear
BO3C 4.10 2 pinion posi

B04A 4.56 2 pinion open 7.5" ring gear
B04B 4.56 4 pinion open 8" ring gear
B04C 4.56 2 pinion posi

B05A 3.15 2 pinion open 7.5" ring gear
B05B 3.15 4 pinion open 8" ring gear
B05C 3.15 2 pinion posi

B06A 3.91 2 pinion open 7.5" ring gear
B06B 3.91 4 pinion open 8" ring gear
B06C 3.91 2 pinion posi

 

Ok am i missing something if the first digit is B = 8" ring gear why is B05A 7.5" ring gear in the examples