O.K. I found the Ford part numbers for the 4 inch rear blocks. Are they correct?
F81Z-5598-GA
F81Z-5598-FA
Second does anyone have the correct number for the U bolts that I'll need. Have been unable to find it on here.

The parts guy at the dealer was not much help either. Thanks in advance,
Will-

 

I found this site: Genuine Ford Parts

Look under the collision catalog, rear suspension

 

Thanks for the info. Now can you tell me do I just nned to get U bolts for an F-350? I'm not sure what I need to get this done.

Thanks,
Will-

 

I would imagine so, if your using the blocks you would want the U bolts also, Im not sure if the 250 and 350 run the same or not.
Do yours have enough thread to add 2 more inches?

 

you can use the stock 250 u-bolts. as long as you can get a nuts
worth of thread it will work.Just put set on my 01 real nice .

 

I bought the u-bolts from fox-performance.com . You also can use ubolts for a F350 SWB.