I've never seen a set of drip rails either in my years of owning Pontiac's. I do have an old set of valve covers with the drip rail spot welded in. I think they came off of a 74 350. I was going to get those rechromed, but someone said I might have clearance issues on the 64 heads I guess you don't have the drip rails on your 455 either?
Did you pull one of the covers off to check ?? Maybe I should give Dave Bishop a call and see if I need them?? He pumps out some high horsepower Pontiac's and I don't think he has drip rails. I only know of the valley brace he uses
Sorry Kim, the 455 is gone to Calgary with its new owner and I totally forgot to pull the valve cover to have a look. I'll keep my eyes open for drippers.