I talked to Mosley a few weeks ago and he’s still running the in-line Walbro Pump on his 5.3 60 swap.internal gas pump (inside the tank) is the better option. I have a walbro external pump and its been fine and you can hear it from outside the truck if you are close to the passenger side frame, but its not that bad (it does not bother me). But all things considered a in-tank fuel pump is best. Yea I can change my fuel pump on the ground without removal of the gas tank but thats really not that much of a plus, given that I've never had to do that.
Talk to mosley motors on in-tank fuel pump setup, II believe he did a nice write up some-where or maybe he has info on his web site.
Is the main attraction to the in-tank Pump strictly noise? I’m not sure I’ve ready many negatives other than that. Not having to drop the tank is nice too.