The life of a Magnum (and 46RE question)

I've put about 20k miles on my mpfi 360 / 46re setup in the last couple of years and it's awesome. Dropped in a 60-70k mile 360 with just a tune-up. I did end up putting on the hughes engines lower plenum plate because it was using oil, but other than that, stock efi, stock ecu and it's enough to melt the 245/45's and gets way better mileage than the turbo /6.
Tunnel mods are some work, but not super complex if you plan it out. The actual trans support mount modification is harder IMHO ( to make it strong enough and actually line up with the trans mount pad )
I'd rather mod the tunnel than convert to carb.

I'd also not think twice about dropping in a 150k plus motor and running it, I just happened to find a low mile motor out of a wrecked truck.