SBM water pump questions

[guido]

Hi All,
1. It's my understanding the water pump from a 273 SBM is the shortest water pump. [Mounting flange to pulley face. Milodon Hi-Flow 16251 is 4.75"]
2. What is the stock water pump height? and is it Cast Iron or Aluminum?
3. Which cools better? Hi-Flow from Milodon or the stock 273 water pump.

When I asked this question before some people told me the Hi-Flow pumps may not give the coolant enough time in my 3 row radiator to cool down
I will also be using a Shrouded DERALE 2400 CFM electric fan with a PWM variable fan speed controller
I am swapping from a 273 to a mild build 340.

Thanks everyone for helping!

 

[junkyardhero]

for the early cars, and until 70 it's cast iron

this is my choice for waterpumps and has been going on darn near 30 years.

1963-1969 MOPAR Dodge Plymouth 273 318 340 Poly wedge water pump

High Flow pump 1701-3 for the MOPAR 273 318 340 engines has a CNC machined billet impeller designed with more vanes and a reduced impeller clearance to achieve greater flow rates and higher block pressure. A Type II Class II military grade anodize surface coating protects against corrosion.

flowkoolerwaterpumps.com

the "not enough time in the radiator" myth has been largely dispelled. although there's still some hangers on of this backwards thinking.

having the the correct sized pulleys is more important that a lot of other factors.

 

[Dartvader440gt]

In my 65 Belvedere wagon, I replaced the stock 273 with a late 70s 360. I used everything from the 273, bought a new early waterpump so I could use the stock radiator, and all the brackets for alternator and PS pump. I've had this setup for 2+ years and even in hot humid New England summers it's been fine. One issue is that I have to remove the PS pump to set the timing. It's opposite of the 273. I think another issue was the heater/defroster hose may have been different also. I just changed out the nipple. Just make sure you have the correct pulleys. I had to mix and match a set.

 

[dano]

Pullies need to match the pump or you'll have alignment issues to contend to.

As stated 69-down is iron and short, 70-up is aluminum and long.

 

[Professor Fate]

Hi All,
1. It's my understanding the water pump from a 273 SBM is the shortest water pump. [Mounting flange to pulley face. Milodon Hi-Flow 16251 is 4.75"]
2. What is the stock water pump height? and is it Cast Iron or Aluminum?
3. Which cools better? Hi-Flow from Milodon or the stock 273 water pump.

When I asked this question before some people told me the Hi-Flow pumps may not give the coolant enough time in my 3 row radiator to cool down
I will also be using a Shrouded DERALE 2400 CFM electric fan with a PWM variable fan speed controller
I am swapping from a 273 to a mild build 340.

Thanks everyone for helping!

Water pumps are dictated by year, not by engine size.
1969 and earlier smallblocks (of all sizes-273/318/340) used a cast iron, driver's side inlet water pump with a 3/4" bypass fitting.
1970 and later smallblocks (all 318/340/360) used an aluminum, passenger side inlet water pump with a 1" bypass fitting; AC cars had 6 vanes and non-AC cars had eight vanes.
The early iron ones were shorter than the later aluminum ones, I can get you the exact measurements tonight if nobody else comes up with them.
But be aware that these are not directly interchangeable without modifications of some sort along the line- the different inlet sides and overall heights means that they take different timing covers and harmonic balancers (because the timing marks switch sides), different radiators (because the inlet changed sides), different pulley sets, and different accessory mounts. You will also need to adjust the intake manifold and water pump bypass sizes and hose to be consistent with each other.
As far as which one cools better, I haven't seen any difference as long as everything is properly installed and functional and the tune is good.

 

[guido]

I just purchased here on FABO a 1969 timing cover with the timing mark boss on the passenger side to accommodate the driverside inlet hose on my 3 core radiator
I am contacting flowkooler now about the waterpump 1701-3

 

[guido]

I purchased the FlowKooler 1701-3 waterpump yesterday,
Thank you everyone for help.