I intalled new solid mount in my rear diff, everything when fine, but now the lower Cup mounts that go on the underside are supposed to be factory torqued to 54-69 fl lbs.

How tight should I torque it? I hit it with an impact gun so I compressed the rubber "Kings crowns" looking thing pretty good. I exposed 4 new fresh threads that where normally covered up with the old mount

 

I bet you work at a Mazda repair shop... Thats who taught you that an impact makes a great torque wrench!!

Go to the parts store and pick up a torque wrench. They arent that expensive.

 

i have a torque wrench, I dont know if I will mess up the drivetrain alignment if I over tighten the rear mounts once I replaced them with the solid mounts.

I have a feeling stock torque settings dont apply here.