I wouldnt worry about it as the FPR will keep the fuel pressure in line. An extra large pump will just result in more fuel returned to the tank. Only an under sized pump would cause a problem and I doubt any after market pump would flow less than an oem.
Automobile(s): '91 Sedan DeVille Silhouette Special
High Point, NC
Re: 4.9 fuel pump question
The problem is too large of a pump will heat the fuel and cause undue stress on the entire system, causing things to wear out prematurely.
I'm looking at either a Trick Flow or Summit 43gph. I think the Walbro 255lph (65 or so gph) is entirely too large. If anyone can chime in with a definite flow number for the stock unit, I'd greatly appreciate it.