I just did some quick measurments, calculating how much thread would still be needed after the blocks were removed. I would guesstimate that the new ubolts are ~2.5 inches longer in total over the block ubolts. They are threaded to about a inch before the "u" in the bolt (granted these are still the square bolts and not rounded bolts, just for clarity) They do come with the hardware, but keep your old stuff too, not 100% on the quality of the given hardware.

These are generic brand, so they are meant to be able to fit on a wide varity of vehcials. I reccomend measuring the ubolt currently in use, width and length. When you find a possible replacment, measure its width and length, and take ito consideration the amount of thread, and also how much thread will be exposed after the block is removed.

 

I just ordered a pair of the 14 inch 125 lb springs