The process isn't that complicated if you haven't finalized your driveshaft and your U-bolts are long enough. On my "adjustment" I chose to do it so I could use the unaltered stock S10 shortbed driveshaft and my "lowering kit U-bolts" (from AutoZone) were already on hand.
I used a 5" long chunk of 1" thick X 2" wide flat stock with a hole drilled (centered at 2-1/2")and tapped for a short 5/16" bolt whose head would slide up into the center hole on the spring perch. I drilled a 5/8" diameter hole 1-1/4" forward of the tapped hole, deep enough to accommodate the thru bolt of the spring pack. Additionally, the bottom plate needs to be drilled forward so everything lines up properly.
Cletis has a good point......you're the only one who is going to notice the move. If you have to spring for a driveshaft modification and new U-bolts and the time to fabricate the blocks and install.....well, it's your truck so it's your call!!!! But the: "rebuilding an old truck is not about getting to the destination but enjoying the journey."
Dave