Technical SBC Water pump ??'s

At my age you would think that I could answer my own question, but I can't, even on Miss G.

Two used SBC short aluminum pumps, for mocking up the Desoto.
The one on the left has 1-3/4" water neck and 3/4" shaft, and the one on the right has 1-1/2" neck and 5/8"
shaft.
1. Why the difference in neck size?
2. Is there an aluminum pump with 1-3/4" neck and 5/8" shaft? Yes there is:

Looks like Summit has ProForm and Edelbrock at a considerable difference in price. Why the big $$ variation?

Local parts store is no help.
"Duh, if I knew the year I wouldn't be asking."

Thanks, guys!

 

used to be that some Corvettes got the larger shaft size.

Also, later models tended to use smaller hoses.

They went to reverse rotation around 1985 on Corvettes, too. Pump on right looks like one of those? Pump on left is aftermarket, probably pretty old. Nice part.

 

Thanks!
The one on the left is a Howard Stewart. Top shelf stuff.
Don’t know anything about the other one. Been in the spare parts room, waiting for mock-up. Didn’t notice the hose thing until I put them side by side. I actually have another one!

 

I'm pretty sure the one on the right is 85-91 Corvette with the reverse rotation pump. Look it up...you can compare details. rockauto.com is a good place to find pictures of replacement parts.

 

There is also a different Flange height/distance between short SBC waterpumps depending on whether it had a generator or an alternator [most aftermarket pumps are for aleternators]

 

Thanks! I believe you nailed it.
That one on the right sure looks like OE, ‘85 Corvette, reverse rotation, serpentine belt on RA.
Won’t work for me.

Any input on ProForm vs. Edelbrock?

HHH sells the Edelbrock, but it’s big bucks.

 

Isn't Proform one of those offshore cheapy brands?

Other than that, either run an iron pump, or get an old aluminum one rebuilt. And find the correct pulley and fan to work with it.

 

That was one of the hardest on my SBC small pump, Was finding correct pullies that lined up with each other.. and not spinning the pump to fast.. Glad I had a stock pile of parts..

 

Yes, Proform is cheap imported copies

 

Thanks, that explains the difference in the $$.
Might just rebuild the Stewart pump.

 

I've heard good things about Stewart pumps... @Dave G in Gansevoort, care to chime in? You had some good recommendations for the 400 SBC back in June regarding Stewart pumps.

 

Send the Stewart pump back to them and have it rebuilt. IMHO they are some of the best you can get.

 

^^^^^ Thanks! I’ll look in to that!

Update: Called and talked to Jeff, the manager. Three day turnaround, Around $75 plus return!
Great service. Too easy in today’s world.

 

I ran a nice weiand pump that I polished for a number of years. When it leaked I called them for a rebuild/ parts , they told me they don't support that. No to a rebuild or parts ! Pump went in the aluminum barrel !

 

Pay the extra coin for a Stewart pump, they can be rebuilt when you wear it out.

 

Well worth it. You saved a bunch this way.