Here's a link
to the Ravelry page. I don't have this pattern but there are a couple of things to try. It looks like the pattern for the cuff blends into the heel pretty nicely. Are you seeing that with the transition that you're doing so far? Is it possible that there is an extra stitch in the heel transition chart at each repeat?
See if the stitch counts with the 3 extra sts make sense for the heel and for the gusset of the sock. If not, can you tell where they're off and decrease to remove the extra sts? The other is to continue with the column 1-3 repeat and see if it looks better as you do more rows on the heel. Sorry not to be able to give you any better advice but perhaps someone who has this pattern will be able to help.