Hey guys I have an sc300 from 92 with an r154 and I recently blew the diff and was wondering if I could drop in an sc400's 3.9 diff without having to change the drive shaft. Is it the same size? If anyone knows please feel free to comment going to get it now so the sooner the better.

 

yes.
the pumpkins are interchangeable.
I think you will have to swap the companion flange though. but im not 100% on that

 

Just measured mine and compared it to a 92 sc400 diff and the companion shaft is off by 1/16th lol

 

what he said, although you may want to look into the later year v8 3.2 ratio versions if you are looking for more gear up top now is the time to do it.

 

Yep, I have an SC400/430 rear diff in my SC300. Just had to swap the flange, pretty simple.

 

Thank you for all the info dudes much appreciated

 

That's odd, as I have an sc400 and threw a 96!auto 300 diff in mine, bolted right up

 

I think the lower ratio ones you have to swap the flange like if its a 430 model. the 400's might be the same but its pretty easy to look at it. 1/16 off sounds like its probably the same.

 

Yeah I mesured mine next to the flage and the other one starting from the flange face. Guys quick question do you think solid diff bushings could cause the diff to just fail over time (loose teeth or even just exssesive wear)?

 

Excesive *

 

* excessive haha

From my research the auto 96 300 diff I threw in is a 4.27 iirc, stock was 3.9. I definitely lost like 4mpg average

 

op what do you mean by blew the diff?? iirc these are pretty stout rear ends..

 

I have a feeling the differential was spanked on before I bought the car but I went to drift a corner and it broke off two whole teeth on the gears (not ring or pinnion) if only I could post the picture of it when I cracked it open. **** wasnt pretty and the gear corresponding to the right wheel had all the teeth grinded down to almost nothing.

 

Probably ran low on fluid at some point. I let one seep a little too long and same thing happened. Diff low on fluid plus clutch kicks equals bad things. RIP my 4.08 factory 5 speed diff.

 

I'm gunna have to monitor the new one lol its not brand new but when I cracked it open there wasn't even a single metal shaving and the old oil still had some good color to it. Wasnt completely black.