Yes. By the distributor, there's a 3/8-NPT plug. It will have a 5/16" "square" drive if original. SnapOn has the correct socket. It won't "just unscrew" (DO NOT try it without following the instructions here, as it WILL "round out" and become a NIGHTMARE!). It's a tapered pipe plug and will need 'heat" to get it out. Heat the plug with a torch (propane or butane probably won't cut it, acetylene is called for) until it glows red (JUST the plug, not the block around it). Immediately hit it with some wax (candle, canning, etc.). It will then unscrew, usually fairly easily. This will give a clear view of oil pressure INSIDE the engine. You'll need an adapter to hook it up.
Jim