I did mine right side up, adjustment rod on bottom, because I am using an angled headstock. I used the routher with a 1/2" bit for the access hole on the headstock and made it a little deeper than the channel and drilled a hole thru under the nut area. I was also worried about just using silicone to hold it in place, thats why I was thinking just rout to the end of the blocks. but after routing it with the bit from stew mac for the hot rod there is no movement at all because it is a tight fit. You have to press it in, so its a really tight fit. I am happy with it so far. Tomorrow I can rough cut the neck and headstock out and start shaping.