Replacing rear end - do these match?

2000 xlt 5.4, axle code 17 (3.31, 8.8). Rear end went out - instead of getting it repaired, I went to salvage yard and found another Expy, (1998, I believe, definitely a Gen 1) with same axle code 17. (The front on the donor vehicle was heavily smashed in, so I'm thinking the rear end is probably still good.) Thought I was on the right track - -purchased rear end and got it home but now, when I'm starting to take the bad rear end out of my vehicle, I notice that the brake calipers on my vehicle are heavier than on the replacement part and, also, the wheel studs on the replacement are smaller diameter than the ones currently on my vehicle. The bolt patterns on the rotors match up on both rear ends. What is going on? Am I getting ready to replace with the wrong part? Both diff covers are 10 bolt, appear to be the same but I haven't actually measured anything with a tape yet. Advice? Will the hubs/axles unbolt and transfer over so I can keep the larger setup on the 'new' rear end? The rotors appear identical. I just put new calipers on the Expy literally days before this vehicle went down, I hate to walk away from new parts. Thanks for any help.

17" rims on my Expy - I didn't notice what was on the donor vehicle. Someone at a parts store thought this might be a rear end from a 1/2 ton truck but it was definitely removed from an Expedition.

I was just checking bolt sizes for the two model years....

1998 - 12x1.75
2000 - 14x2

Same bolt pattern

So at least that part makes sense.

Differentials look to be the same... 8.8" 31 spline. So if gear ratio is the same you should be good to go.

Even 2000 uses both rotors, 12mm and 14 mm studs. I know cause I have 2000 Eddie Bauer. Push come to shove, if rotors and calipers won't swap, see if the wreckers has the bigger stud rotor rear end. All first edition 97-02 expedition and f150's use 5 x135 mm lug pattern. The heavy duty vehicles used the14 mm ones.

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