taking out rear blocks

I am thinking of just taking out the rear blocks from my 99' F350 DRW to level it out. Do I have to completely take off the U bolts or just loosen them enough to slid the blocks out and also would I need to get new U bolts or will there still be enough threads on them to screw the nuts back on? And also does this affect the drive shaft angle enough to cause any problems? Any input would be appreciated.

Thanks

You will need to get about 1" of clearance to make room for the pins. You might not have enough threads to reuse the u-bolts, but that aside, they would be stretched and probably have the nuts fused to them. It will be easier to cut the old ones off and replace with new.

you should always use new u'bolts but chances are you will need new bolts anyway