Leafspring wedges/tapered shim install question

[Dodgeboy]

Whats the deal with all these companies who sell leafspring wedges recommending that you bolt the wedge to the leagspring pack? Do most "newer" cars/trucks not have a long/tall enough leafspring locating dowel?

I recently lowered the rear on my '74 challenger, making the car sit level in preperation for installing taller tires. My back bumper sits pretty high with my 29" tall tires and I'll be installing 31" tires before summer is over. To correct my pinion angle, I fab'ed up a 5° wedge (1" high) and will need to reinstall (add) the 3° shim that I had removed, (total 8° of wedge/shim). Mopar service manual says not to use a shim thicker then 1/4 inch as the locating dowel (5/8" high) doesn't stick into the axle perch enough. Now that I know how many degrees I need, I will be buying a 8° shim and removing my current shims. I have a extra axle housing that eventually will be installed (long term plan is to shorten the axle) where I will just re-weld the perchs.

This is with mopar SS springs and switching from using the front mounting bracket lower hole too using the upper hole. This change alone lowered the car roughly 1.5" incase anyone wants to know

 

[moparlifer]

I had a aluminum lowering block about 2" thick i cut down to 1.75" thick. it came with a cast-in locating dowel on one side. you could make something similar to "extend" the dowel on the spring-pak via a doweled spacer block / shim pack (IE Plug weld the dowel into one side of the shim-pak

 

[Dodgeboy]

This is basically what I ended up doing, I made my own shim, welded a dowel onto it, amd made the shim deep enough so the factory dowel fits inside. Also after looking at shims I think I will just leave my 2 shims in there and call it done. A 8° shim is 3/4 thick and even a 6° shim is 5/8 thick, thats not gonna work when the factory dowel is 5/8 thick and I don't have time to bolt the shim to the leafspring pack (got 1 toddler & a 7y old). My driveshaft operating angle is good so we'll just call it good.