V Belt on Magnum are my thoughts clear
All great information above!
I sent my Magnum cam to Oregon Cam Grinding for a regrind, which meant I would need an electric fuel pump. Then used a 70 ish (?) timing cover and blocked off the fuel pump hole.
Then I used everything else off my LA: water pump, power steering pump, fan and all v-belt pulleys.
The only issue is with the Magnum timing marks. Magnum engines have the timing marks on the drivers side. The later timing cover also has drivers side timing marks so the marks work with the harmonic balancer marks. BUT, the earlier water pump with the drivers side output makes it difficult to see the marks. I painted a line on the cover, and three lines on the harmonic balancer (TDC, 20, and 36) to help. Some time, I'm going to fabricate a pointer on the passenger side. Lots of room there.
Keep us posted on your build.