My take on the oiling system crossover tube for the small block

Wanted to say Thanks for posting the videos. I am doing most the the GJ oil mods now and seeing you drill bit "walk" and ruin the block is concerning. I had planned to drill the mains to the oil galley with a 9/32" bit....is there a way to keep it straight to avoid drilling offline??? Is it better to have a machine shop drill these??? Thanks Guys!