Rotorblade

Hello guys,

Since I bought my vette has been a complete headache not having the original, or at least a 350, engine fitted in. I have to replace the water pump because it has play on the bearing hence is leaking water through. I am completely convinced my car has a 400 sbc because the GM casting number stamped is 330817. Today I realized it has the original 350 SBC water pump fitted because it has the number "30998" stamped.

I need to replace this water pump for a short type with a Pilot diameter of 0.750 in and compatible with a 400SBC. Which one would you recommend me? It is the first time I am going to replace it, any considerations or precautions? Do you consider I have to replace the thermostat as well or depends on the type of water pump I am going to fit in?

Thanks for your help and time.

76strokervette

You must use a corvette water pump for pulleys to work and have everything line up.
Any sbc water pump will fit the engine but only a corvette unit will work with the car.

Rotorblade

When you say Corvette water pump What do you mean? As long as the water pump which is going to replace has the same lengthen and can fit the puller with a Pilot diameter 0.750 would be compatible, isnt it? The main problem I have is the engine I have fitted on my car which is not an original corvette engine.

jackson

wp for a 350 pumps same volume as wp for 400. Match pump to whatever brackets and pulleys you have on your motor. In addition to short and long pumps there are corvette pumps.

Rotorblade

I didn't know they were special corvette pumps, Where Can I find them?

Another question I have is the wp I have fitted does have a port for the heater with a hose installed. But this hose goes from the pump to the engine, is not going to any radiator. Can I simply buy a wp without this port and plug the other end which goes on to the engine?

76strokervette

Corvette water pumps have the .750 shaft and are a short version. They are different than the regular short version and
you will have alignment issues with any other water pump as stated above. Edelbrock has all the dimensions on their website if you want the
exact numbers.

derekderek

You are sure you have a .750 diameter pilot shaft? Then that's the pump you need. The most common is the 5/8 diameter shaft.

jim2527

click one of the sponsor links to the right >

jim2527

So.....There are 2 versions (or 4?) versions of the 'short' water pump.

Typical short pumps are 5.6255" in depth, thats from the block to pulley flange
Corvette specific short pumps are 5.8125" in depth. This is where pulley alignment issues come into play.

Then you need the proper pilot diameter as mentioned above..

Rotorblade

When I measured the depth of my wp I thought the bearing was displaced forward because I was measuring around 5.8" and didn't match what I believed was the right replacement of a short pump which as you said is 5.6"

As far as I know the pilot diameter should be 0.75 for corvette WP. I don't know if I am mistaken on this too.

Do you guys think this could be a good replacement? https://www.edelbrock.com/water-pump...5-7l--v8-64970

As I said above, the wp I have fitted it does have 2 ports, but in my case the hose for the heater is going straight from the engine to the pump, which is doing nothing because is not going through a heater. Can I just blank the port on the engine and buy a wp without this port?

derekderek

somebody by passed the heater core and just ran the loop hose to the two heater outlets on the engine or excuse me one on the engine and one on the pump. Yes you could block off the other one. It doesn't really have to have the water flow through that hose. Get a set of calipers and double check the pilot diameter. You could probably get away with the ruler but...

74_stingray

"Do you guys think this could be a good replacement? https://www.edelbrock.com/water-pump...5-7l--v8-64970"

The Edelbrock 8812 is what I used on my 383, it's pricey but I wanted aluminum and it looks good with the Edelbrock intake on my car. It is a short water pump for the Corvette.
Eddy

Peterbuilt

You can buy a water pump at your local auto parts store.
Here are the dimensions:


To bypass the heater core buy a 5/8" to 3/4' adaptor or get a 5/8" hose and temporarily squeeze it onto the 3/4" side.

While you're at it get new top and bottom radiator hoses.
Replace the thermostat with a new 180*

jim2527

"Good' is a relative term. There are 'good' pumps that cost a lot less.

Sigforty

Rotorblade

Thanks to everyone for the advice and help. I already ordered a new water pump.

Jebbysan

I went through three wrong Team G water pumps and one that came straight from Holley.....the hub was pushed on too far on all three.
Wanting to drive my car....I bought a new replacement from O'Reilley for $40......it was the correct Vette pump and it cools my 406 just fine.
Been on there 3 years now.......no issues.

Jebby

Rotorblade

it is what I did, I went to rockauto and bought one that will do the job for sure.

Thanks

jb78L-82

Buy a Stewart water pump and be done with it. I have had mine for 12+ years on the OEM L-82 and now on the rebuilt/upgraded L-82 355-cools like a champ and still going perfect all these years. I would not buy cheap junk water pumps and never a rebuilt one......Stewart is top quality/expensive but will last a long time.................