correct front diff?

[RedlineRex]

i was taking a look under the sy and noticed that the front diff is not the original. it appears to be a used one since there is a "91" marking on it using the paint pen (or whatever they usually use at salvage yards to label their stuff). this makes me a little nervous now, are there any markings and/or physical difference between a sy/ty front diff and possibly a 4x4 s10 (if they are even interchangeable)? could the gears possibly be a different ratio than stock?

any info would be appreciated... -paul

 

[protosy]

check the passenger side. If the axel tube has a shift cable it is a 4x4 not awd. the other possibility is the input flange could be a cardin joint (u-joint) type flange as opposed to the standard round flange that the standard constant velocity joint hooks to.

those are the ways i know of...
chad

 

[nomoty]

As long as there is not shifter cable on the diff. it is fine I swapped mine out for one outta 84 4x4 after I rebuilt it of course but they are all the same with a few minor differences.