Are the two bolts replacable on the rear diff mount? They're the bolts that come off the unibody/frame and goes through the diff mounts, which are then fastened by a pair of nuts.

The threads on the bolt are severely damaged.

 

I've used the rear passenger side seatbelt bolt hole(near the diff) and retapped it for 12X1.25 and stuffed a bolt in to limit the differential's movement up and down, works great, but I get some noise, also put a rubber piece on the end of the bolt where it lands on the differential housing. I have a design for a piece that uses the exhaust hangers on the cross member for a mount that pulls the differentail down...

But to your question, that's actually the differential mount that has the studs sticking out, so you'd have to replace the diff mount, which can be a pain, but it can be done.. My subframe mount acutally broke off which means I'd have to replace the whole subframe... Gggrrr...

 

no, I'm talking about those studs that stick out from the bottom of the car, which go into the holes on the "wings" of the differential, those studs are in very bad condition.