It sucks,but you can lie over the engine using some plywood or a plank across the fenders--after taking the air cleaner off ,and get at the area behind the distributor ,use some gunk engine cleaner,brake cleaner,etc,and hose it off good...you can "powder" the area with cornstarch or baby powder,flour,anything to make a fresh leaks source more visible..
If those intake bolts are where the oil is coming from it may take quite awhile for enough to build up and get blown back towards the firewall,like a few days of daily driving..other sources of leaks usually wont take that long--a valve cover leak will show up almost immediately in most cases..