'78-400, Alt. & pulley?'s

Hey all!

I have just brought home my '71 Duster. It has a '78, B block 400. The radiator and water pump for the late year 400 are all set up, line up and work. It was a A/C set up. I will not be using the A/C. This cause's a problem with the pulley's. The A/C guided the belt past the W/P and did not go around/or use the W/P pulley. Without the A/C pump, I have the belt hitting the W/P.

And for pulleys, I would like to use the March serpentine pulleys with a single belt. (The car has manual steering.)
I would like to use an earlier Alternator and bracket set up. Can I use an older set up on the later W/P housing? I'm hoping the earlier Alt. & bracket can be used and clear the belt issue up with it all being lined up with the March pulleys.

Has anybody done this?