Shimming the cab will do nothing to alter the hood fitment at the cowl.
Sounds like you need to make more adjustments to the hood to bring it down further.
Remove both hood springs. (very important)
Loosen outside hinge bolt, passenger side.
Place a 4 inch block under nose of hood.
While an assistant presses down on the hood, loosen the two inside hinge bolts on the passenger side. Once your assistant says it went down, tighten the bolts.
Remove 4 inch block, close hood.
If the hinge won't go down far enough, you will either need to hammer down the cowl and/or open up the holes in the cowl (as per Truck Shop Manual).
Carl
Last edited by 52Carl; 12/31/2016 5:37 AM.