Has anyone figured out how to get rid of the smog pump on the 1969 472. I know how to remove it and plug the tubes but what about the belt tensioner issue? Thanks.
http://smileys.smileycentral.com/cat/15/15_1_111.gif (http://www.smileycentral.com/?partner=ZSzeb001_ZNxdm414AHUS)

Use pulleys from a 425 or maybe a later 500 that didn't come with an AIR pump.

I am rebuilding a 1969 to replace a knocking 1974 472. If I understand it, can I just remove the smog unit entirely and reroute the belts? What other options are there and what must be plugged up (air inlets)?

I think you're gunna find that re-routing the belts doesn't work.

I have a '72 500 that originally had a smog pump. I got ahold of MTS and asked them to send me what I needed to make things work with the pump removed. I got a 425 crank pulley and a 425 water pump pulley. You also need the timing pointer from the 425......it's plastic, unlike the earlier stamped steel piece. Your timing marks will always be off if you try to use the early pointer with the later pulleys, or vise versa.
I need to get all that stuff put together so I can see just how everything fits.:bonkers:

There are two other options which I have used numerous times with great results. Although a bit unorthadox.

Option 1: There is a gates belt (can't remember p/n) that fits perfectly between the crank pulley and the water pump pulley. To get the belt on, you should ground ignition coil tower wire and carefully bump the starter. With a little practice you can be back in business within a couple minutes (perfect for those occasions when the smog pump seizes away from home.) Like I say, this method is tried and proven and has been used (by me) for hundreds of thousands of miles.

Option 2: Get an old smog pump that still turns. Disassemble the smog pump (it is not difficult at all) remove all parts that are on the inside shaft (they slide out easily). Then simply grease the bearings with a little high quality grease, then re-assemble. You now have a nice, but large, belt tensioner. Very reliable and easy. Again, another tried and proven method. This method is great for places that require emission devices be "in place" but not checked for functioning.

I hope this helps. In any event you will probably be amused.