I bought a nice set of 33x12.50x16.5 with wheels but when loaded they rub the top lip of fender well...think a leafspring lift block would be ok to keep my tires from rubbing...or can they slip out or break...just looking for a cheap fix

 

As long as you replace the block and dont try to stack them you will be fine

 

The lift blocks are usually located by the hole in the spring perch and a peg and matching hole in the block and the spring stack centering bolt-the tension of the U bouts also helps keep them in place and there is almost never a problem.

Something to consider is that the lift blocks should be tapered to maintain the pinion angles relationship with the trans tailstock angle,a big lift distorts the driveline angle a lot.

 

what about using coil spring spacers on the front or will the diesel be to heavy for the spacer