"Any reason not to do this?"
Hummmmmmmmmmmmm. A few questions. Why would you want to modify the proven design of a fuel system that has been working fine for +20 years? Why would you change out a pump that is currently working fine? (I'm not saying the fuel pumps are without issue and don't wear out)
Do you have a specific reason? Any specific problem you are having? I'm not saying there aren't good reasons to make changes, just that I would like to know your specific reasons.
Do you understand that making changes could possibly complicate the system and REDUCE the reliability rather than IMPROVE it?
When I was I kid, my friend "thought" he needed an additional fuel filter on his car. So he installed one not realizing that the plastic filter he selected and mounted was too close to the manifold heat control crossover. His filter lasted a few days before it melted spilling pressurized fuel in the engine compartment setting his car on fire. 100% his fault! Come to think of it, my friend is now dead because of another silly mistake he made which I won't go into here.
Chum lee