It's been a while since I've messed around with pouring soft baits, but I have heard that dimpling could be caused by the plastisol cooling too rapidly. Adding a heating source under the mold may help. You could also try pouring the plastisol at a cooler temp/heating the mold before pouring to try decreasing the speed of cooling. Again, I'm not an expert when it comes to plastisol, but I have had some success using the methods mentioned...