Plan on installing myMagnaflow Catbacks today, and I was considering using a floor jack to get the car up on jackstands. After I read the manual, it says in bold letters: Don't use rear end as a jack point! Will I hurt the rear end if I use a floor jack there, or was this just a safety precaution by Ford?

 

IMO you would not want to use the rearend anyway, it will be an easier install if it hangs free, should give you more room to manuever the old ones out and put the new ones in..Good luck.

 

safety precaution. putting the cars weight on the rear axle/rear end will not hurt the car. think about it. When the car is on the tires...the weight is on the axle. When I did mine...I placed two jack stands...one on each side of the differential...half way between the rotors and differential.

but make sure the car is secure (parking brake, level, block the front tires). If you don't...you might "become one with the stang"

 

I would think you should be okay as long as you use the axle and not the differential casing. The axle will be very rigid, since as the prior poster said, it always supports the weight of the car. The differential cover though would likely bend, so I would stay away from it.