Magnum\LA Hybrid, Different timing cover?

Hey guys, I have a Magnum/LA hybrid 360 ( http://www.classicindustries.com/mopar/parts/mn2472.html ) and I'm wanting to go from the serpentine water-pump, to the older style v-belt setup. None of the regular mechanical pumps fit this front cover, they're close, but no cigar. From what I've inconclusively read on here I need to switch to an earlier style front cover to run the older style w/p and pulley setup right? Is the early and the late front covers the same bolt patterns? Thanks for the help guys. :prayer: