Will a front differential from a 83 fit in a 93? or are at least the parts inside the same?

 

I do not think there were any design changes in that range, but you would probably want to check with some kind of interchange list first. Most junkyards have access to such a setup. You would need to make sure that the gear ratio matched.

 

Is it stamped somewhere on the diff or where do I find the ratio?

 

The easy way is to check RPO codes for both vehicles.

Gear ratio codes usually start with G:

GU2 2:73 ratio

GU4 3: 08 ratio

GU5 3:23 ratio

GU6 3:42 ratio

GT4 3:73 ratio

GT5 4:10 ratio

Just make sure your donor truck has the same code.There is a manual way to check where you count driveshaft turns versus CV shaft turns but I am unsure of the details of that and not sure how it would work on a front diff.

 

Where do I find the RPO code?

 

RPO sticker inside the glove box or plug your VIN into compnine.com's VIN decoder.

 

That compnine.com doesn't go very far back, no list for my 91 or 87