Unless you're planning on changing the timing gears every few days, why bother to drill and tap the main cap for access to those bolts? Timing gears last about three days past forever, and I can't think of any other reason to remove the timing cover. Even the front seal can be changed by simply pulling the harmonic balancer and leaving the timing cover installed.
My borescope works with a laptop, has a bright light, and comes with a 90 degree mirror for looking sideways. It also fits through any hole larger than .22 caliber (5.56 MM)
Jerry
