After finding some wear on my cam distributor gear, I decided to add a dedicated gear oiler to hopefully eliminate any more gear wear. The hole in the tube is about 0.028"
I put a groove behind the front cam bearing bore/ block . Maybe a .032 x.012 to .015 deep. That feeds the face of the cam to block.Also, the mist of oil lubricates the chain and distributor gear. You would be surprised how much oil is moved through a groove that size.
I use the high volume oil pump on my 350 I have the adjustable unit and TA had made the passages bigger when I bought it. I have never had trouble with it and been in there 25 years + now. Seems the 455 tears them up more than the 350, but Ido have mods done to the block and oil pump, I do not know if all that has helped but it is still ok. couple pics.