[1lowufo]

Ok, I've looked everywhere for a comparison between the AC Delco front & rear Shocks. Seems like there are two choices;
540-210 fronts
540-211 rears
&
503-706 fronts
503-707 rears

Can anyone tell me the difference between the two (540 and 503) thanks.....

 

[JohnWR]

Ok, I've looked everywhere for a comparison between the AC Delco front & rear Shocks. Seems like there are two choices;
540-210 fronts
540-211 rears
&
503-706 fronts
503-707 rears

Can anyone tell me the difference between the two (540 and 503) thanks.....

I think the 540-211 should be 540-251, or at least it is at Rock Auto.

The 540 series are designated as "True Factory OEM", so should be identical to what was on the car when it was produced. The 503 series are "High-Quality Alternative", and are supposed to be backed by GM to meet fit form and function standards.

Of course the cars were originally shipped with Bilsteins, so the replacements are not actually identical in any case.

 

[1lowufo]

Thanks John for your info. The reason for my post is, I can't afford Bilsteins, and I'm looking for a bit more comfort. If the only difference between the 540 series and the 503 series is quality, then the 503 seams the better choice. However if one verses the other in stiffness, then I would like to know that difference too. Thanks.

 

[marksbug]

when I got my blisters foir my coupe in the end they were about the same cost as the others. that was last year @$320 I think, now there up a bit higher like everything else. dont ferget to factor shipping..

 

[JohnWR]

Thanks John for your info. The reason for my post is, I can't afford Bilsteins, and I'm looking for a bit more comfort. If the only difference between the 540 series and the 503 series is quality, then the 503 seams the better choice. However if one verses the other in stiffness, then I would like to know that difference too. Thanks.

They are all listed as FE2, so the stiffness should be the same.

 

[Hurricane87]

I think the 540-211 should be 540-251, or at least it is at Rock Auto.

The 540 series are designated as "True Factory OEM", so should be identical to what was on the car when it was produced. The 503 series are "High-Quality Alternative", and are supposed to be backed by GM to meet fit form and function standards.

Of course the cars were originally shipped with Bilsteins, so the replacements are not actually identical in any case.

Actually, the gmparts.com is listing the fronts, and it lists them as Bilsteins.