1969 Chevy Big Block P/S Pump Difference

[WorkinProgress]

There are two different style big block (396, 427) power steering pumps that are used on the following 1969 Chevrolet car line-up. Camaro, Chevelle, Nova, and Passenger car.

Both big block pump reservoirs had the inlet tube attached to the side of pump, unlike the small block which comes out the backside.

The inlet tube positioning is what determines the pumps application.

The Passenger car pump is used exclusively on that car as the inlet tube points away from the engine and has multible bends.

Camaro, Nova, and Chevelle all share the other style pump which the inlet tube points towards the engine, but there are internal differences.

All Camaro's, and according to the parts book some Chevelle's had high pressure pumps for variable ratio steering.

I have taken some pictures of two NOS GM pumps showing the external differences.

The Chevelle, Nova pump #7806372 can be found in parts book Group 6.605 which shows it is non-variable steering. I have taken pictures of that pump and it has a yellow sticker on it with the letters AF. The GM box is dated 5/13/69. This pump is also cosmetically the same as Camaro.

Power steering adapter kit #3960262 Group 6.508 is for Impala, Caprice, (exc Station Wagon). The pump from that kit has the yellow sticker with the letters AD.

The adapter unit #3960262 instructions shows that the hoses get clamped to the upper A arm shaft bolts, as there is a bracket enclosed. I can only assume that is why the inlet tube on the pump points away from the engine.



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None of the NOS parts are for sale in the pictures, and hopefully this will end the guess work on the pumps application.

- Warren

[bbbentley]

nice work and great pics.

[m22mike]

Thanks Warren, very helpful.

Mike

[XXXGoldL34M20]

Thanks Warren
You really helped me to identify the 2 pumps I have <<GRAEMLIN_URL>>/biggthumpup.gif

[Postsedan]

Almost like the early days of &quot;Hot Rod&quot; illustrations, well done <<GRAEMLIN_URL>>/biggthumpup.gif

Dan

[camaromb]

I knew Warren would have the parts to show the difference. The Camaro only parts are difficult to find. Thanks Warren.

[WorkinProgress]

Thanks everyone for all the positive comments! I'm glad that my info was helpful.....Warren

[Steve Shauger]

Warren,

Excellent tutorial, thank for providing the information.

Steve

[Fisherguy]

I'm looking for a PS setup for my 69 but I've heard from a few places the 69 pump and brackets are a major PITA and I should get parts from a 70 instead.
Looking for comments/opinions.
Thx
Will

[bbbentley]

I'm looking for a PS setup for my 69 but I've heard from a few places the 69 pump and brackets are a major PITA and I should get parts from a 70 instead.
Looking for comments/opinions.
Thx
Will

Purely comes down to do you want the engine to look like the engine came in the car originally? Or do you just want to do an engine swap? The power steering or any other component, for that matter, don’t know or care what they are in or which water pump used. But if you are going for a specific factory belongs there look, then stay with what is correct. Newer style brackets generally do have better adjusting for tension setups.

[William]

Chevrolet service info strongly warns against mixing conventional parts with variable ratio.

“The pump used on vehicles with variable ratio power steering provides increased fluid flow at higher pressure than the conventional pump. Consequently, the conventional pump and the pump used with the variable ratio system are not interchangeable. A new pump outlet hose is required on variable ratio power steering equipped cars.”

-1969 New Product Training Program Booklet

“Internally, the only physical difference between the variable ratio system and a conventional system is the rack and sector gears. However, higher power steering pump pressures are required so it was necessary to strengthen the steering linkage accordingly. The relay rod is now a larger diameter, and constructed of higher strength steel. The same is true for the pitman arm. Because of the substantially higher loads imposed on the steering linkage, variable ratio steering gears should not be installed on any past model cars.”

-1969 Product Review

[bbbentley]

Purely comes down to do you want the engine to look like the engine came in the car originally? Or do you just want to do an engine swap? The power steering or any other component, for that matter, don’t know or care what they are in or which water pump used. But if you are going for a specific factory belongs there look, then stay with what is correct. Newer style brackets generally do have better adjusting for tension setups.

I should have prefaced my previous comments with the following: I was specifically speaking of only brackets as a means to adjust tension on belt. Not, piecing together a power steering system with mismatched components. Thanks

[Kurt S]

The power steering pump off a Cadillac looks a lot like the BB pump, but the inlet faces forward, fwiw.

Thanks Warren (and Bill)!

[AnthonyS]

The power steering pump off a Cadillac looks a lot like the BB pump, but the inlet faces forward, fwiw.

Thanks Warren (and Bill)!


Like this I believe.


and yes, thanks Warren & Bill, very helpful.
Anthony

[Woj]

Similar reservoir, taller tower. Caddy pumps I have seen in the past faced aft, as did the Chevy line-up. I might be missing something though.

[AnthonyS]

OK, was just going by the above... I have no idea what it originally came off of but it fit nicely on my square body BB - the taller tower was helpful in that application, and yes, that is noticeable... it's listed for sale here too FYI everyone.

Cheers, and always nice to share information!
Anthony

[ban617]

Thanks for the info …. That’s is some very nice detailed information on the pumps … We’re there specific power steering boxes that the pumps were paired with on the solid lifter engines…Seems like on the 69 Novas most 396 375hp that I have ever ran across had manual steering…

[AMANOCC]

great post!