The E-450/7.3L combo finally defeated me.
I started out with a rebuilt fuel bowl and two new head fuel lines to install. I was able to get at the two bolts holding the bowl to the HPOP and (after removing the turbo) could get a wrench on the two head fuel line fittings at the bowl. I could unhook the fuel return line and could get a wrench on the fuel inlet fitting but had no room to actually turn the bloody wrench. I could see the head fuel line fitting on the driver's side head but couldn't get a wrench on it.
After an afternoon of cursing and swearing I finally gave up and left the old parts where they were.
I did find where one of the head fuel lines was chafing on the HPOP and put a bit of protection on it so it doesn't wear through and an exhaust leak got fixed at the turbo outlet so it wasn't a total SNAFU but if there's ever a problem with those parts the dealer will get the honor of replacing them.
I've driven vans most of my adult life and the one thing I hated about each and every one of them was working on the effing engines. I think they were created to test our patience and tenacity.
Rebuilding the fuel bowl (once it's out) is a piece of cake. I bought a used one off ebay for forty bucks and rebuilt it so now I've got a spare.