Will a 72 down water pump housing work on a 73 Charger?

[WH23G3G]

Can I change my 73 400 water pump housing back to a 72 housing so I can still use my original 318 26" radiator that fits perfectly in my core support? Are the housings different for a/c and non a/c? I've got mine setup with factory RV-2 compressor on. Problem I'm having is I'm having to swap radiators and mine was originally a 318 with 26" radiator. All the aftermarket radiators have 27 5/8" core so it doesn't bolt up correctly, plus they are only 2 core. I'm trying to fix the problem but don't know if the earlier housings will work with factory a/c, alternator bracket, and power steering. I talked to 440 source and they said their new ones won't work.

[Nacho-RT74]

Yes you can but need a diff brackets for steering pump because the outlet on driver side won't allow to fit it on same later position.  Not sure if need to run also a diff belt setup due the diff steering pump location. Maybe the water pump will require its own belt like earliers and if so, need the belt idler pulley setup for the water pump ( available as repro around ). Not a diff between AC or NON AC cars on the housing.

Dunno if the water pump pulley? Can't tell if the earlier steering pump location changes the crank pulley groove or not. Laters run one belt for both but earliers get its own belt on each one

[sccachallenger]

I did this on my Challenger back in 1985, mounted the PS pump high, like the earlier set-up.
I think everything lined up. The only problem I had was the PS pivot bolt is a loose fit where it passes through the WP housing.
If you tighten it normally it won't hold, and the belt will keep getting loose.
I ended up splitting a Coke can and wrapping it around the bolt to take up the slack.
If I did this today I think I'd drill the holes on the pump bracket and see if I could tap the threads to the larger size.
Bottom line, it worked great, and allowed me to keep my 340 radiator.

[WH23G3G]

What all would it take to convert the bracket setup to a 72 400 w/ a/c. Maybe easier. I believe I read somewhere the alternator bracket is different.