I swapped a 5.9 magnum for my 318la block. I got motor mounts from Schumacher, about $140. Check with them for your application. I kept the serpentine belt. I went with a carb and used an electric fuel pump 4-6 psi. The timing chain covers were different. Magnum swap.com was a lot of help for me
I used sealed power with eq heads and had Oregon cams do a custom grind on the roller cam. I haven't put it on the dyno but it's much healthier! Magnumswap.com was great help
This is my first restoration, 72 Dart Swinger. I built a 5.9 magnum added front disc brakes, 8 3/4 rear end and just had the trans rebuilt. I'm working on the cooling now and see a new harness and ac in the future.