I did a little research last night. My HP Holley carb book has a pretty good breakdown on the "blue" pump and how it should be installed. It has a built in pressure relief that internally routes high pressure fuel back to the inlet port, which is designed to not exceed the max limit of the pump. I think this is what Jack21's comment was directed at. According to the book, what some racers have done is remove the relief valve screw and insert a fitting to plumb the bypassed fuel back to the tank thru a restricted orifice of no larger than .060. The explanation for doing this is that the pump inlet then only receives "fresh" fuel, makes sense to me. There is no other mention of a need to relieve "dead head" pressure, so as far as I'm concerned, my installation just sounds worse than it really is. And a rubber isolator between the regulator and the firewall should help cure most of that.
Mike
Also, the fuel breather on my car (E-M) runs from the top of the tank to a nipple near the top of the filler pipe. If I were to add a return, I would think that is a good place to tee into.