Rocker Arm Shim Alternative?

Hey guys. In a bit of a pickle. Got my Promaxx heads all bolted up just in time for the New Years races. Only problem is my rocker arm alignment is a little off from what it was and I can’t order any and get them here in time. Doesn’t seem like there is much to them, is there a hardware store alternative? anything come to mind?
Anyone in Northern California have a pack or two to sell?