SBM variation craziness ... cooling!

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CultClassik

CultClassik

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This is the part I love about Mopars because they seemed to do it better than anyone - change things up for no good reason! ;)

I've got a 67 Dart, originally a 273 and I've got a later (early 70's) 318 that I just dropped in. First thing I noticed is the old Weiand intake I installed has the 3/4" bypass hose fitting (which may or may not come out, very corroded) and the 318's water pump has a 1" fitting.

So.....looking around, I'm seeing all kinds of water pumps. Ones that take thread-in fittings, ones that have fixed fittings, with A/c, without, with air pump, etc.

What's the real difference? Honestly, I'd be happy with a cheap aluminum model with thread-in heater/bypass fittings. Or not, whatever.

From what I can tell, GMB model 120-1250 is the iron version that's correct for a 67. There is also a 120-1270 which is aluminum, with fixed heater/bypass fittings, presumably a 1" bypass, but states that it's for models with air pump.

What's the deal...are there any real differences, or can I use any SBM water pump given the fitting sizes are correct?
 
Which side is the inlet on ?
Another difference in them.
6 or 8 blade impeller ?
cast iron or aluminum ?
Usually , it's nice to have choices.
Especially when they are clear.
But the small block water pump puzzle can get confusing.
I've had good luck just going to NAPA and getting what was specific to the car , though I have gone with the a.c. ( eight blade impeller ) to improve cooling on a couple deals.
 
Right, choices are nice when they make a difference, but the bypass hose thing really gets to me.

Anyway yeah, I noticed the inlet is on the wrong side. Looks like the correct 67 models are all 8 impeller (that I'm looking at anyway). Looks like the pump that came with the 318 will be wrong anyway, so I'll just buy a rebuilt stock one for now. $25 to get it running is worth it I suppose!
 
Ohhh, the cunfuzun' begins!!! Another problem you will have but maybe have not yet encountered is that the later style aluminum pump with the inlet on the drivers side also has a completely different set of brackets for the alternator and power steering pump. Oh, and the pulley grooves may not line up between the earlier and later unless you start running the dual pulley alternator, unless you happen to have an A/C crank pulley already in place. Even then, I think you might also have to shim the alternator if running a single pulley there, not sure about that!!

Your best bet is to go with either a complete setup from a 67 car, which it sounds like yours is, and you will be able to run all original brackets with the correct passenger side lower radiator bib. Now, if you have a drivers side lower bib, your best bet would be to get the aluminum 70 and up pump, which has the 1" bypass if i'm not mistaken, and use the corresponding brackets for the later style pump.

Confusing ain't it??!! Geof
 
Every single part of the cooling system (including the radiator inlet and outlet locations) changed in 70 so you need to do what Geoff said and change all the parts on the 318 to the earlier stuff to match your cars original configuration or figure on doing a whole lot of figuring out how to make the parts work together. As far as Mopar changing things, practically every company changed things just like that for what seemed no good reason. You really want a challenge? Buy a Ford and do an engine swap on it. With 4 configurations of small blocks and at least that many big blocks they really kept things exciting.
 
Built a few fords,want to get confused?Build a performance FE.Start off with 3 diffent sets of heads and intakes,gets crazier from there.
 
Oh, come on... When I worked at a parts tore, we had over 25 water pumps for Chevy 350s alone. All the manufactureres make changes, and there are usually reasons.
 
You guys are going on a tangent with my whining about Mopars changing things. Fords, I've done a few, why bother. Why even bother with an FE ;) Chevy...never had a problem with big or small block, easy to make tons of reliable power for less than other makes. Honda and Nissan are fun too, and some of my fastest (and easiest swaps) have been turbo I4 and V6 cars! Some of the worst times I has was my 66 Dart 270 when I was doing a 360 swap back in 1993. Not a lot of info or parts (for pre-67) back then. Lack of Internet didn't help!

Anyway, thanks for the help guys. I just ordered a rebuilt stock pump for now. It's just a mild 318 to use for cruising and short Texas road trips this year. I actually fired it last night. Luckily it started without too much fuss...I'm always nervous buying a used engine, but they said it's got about 2k on it and it looks the part! Now if I can get that 904 rebuilt we'll be in business. Pretty exciting!
 
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