is it going to hurt? probably not. Will it suck down some horsepower? Absolutely. That's the concensus of everything I've read from knowledgable people on the internet and in several books on building high performance engines and engine blueprinting.

I haven't priced out blueprinted pumps. I just know that a lot of the Cobra guys use the services of one of the turnkey builders. He'll blueprint them for $75 plus shipping. I guess that's pretty pricey when you consider the cost of an OEM replacement pump (I just looked it up and didn't think they were that cheap).

In your case, since you're just freshening up an old 5.0, I'd just slap in a OEM replacement pump and call it done. If/when you build a fancy motor, then I'd go for a blueprinted pump (hv if necessary)