1966 427 390 Leaf Spring

[Tony C.]

Hi
How can I tell the difference between a original or repro 9 leaf rear spring for a 1966 427.
Thanks Tony

[Gary B.]

Original 9-Leaf Spring

Tony,

Find someone with a known original mid-year spring and study the up-turned ends on leaves 2-9. No repro spring has the correct configuration of the upturned ends. The differences are obvious once you know what to look for.

Gary

[Stephen L.]

Re: 1966 427 390 Leaf Spring

Here is an over-restored original 67 427/390HP spring.

[Gary B.]

Steve: Nice photos! *NM*

[Wayne M.]

Another possible identifier: "GLS" forging

Check back to this archives link:

https://www.ncrs.org/forum/archive28.cgi?review=244700

I show a pic of the Great Lakes Steel ident on the edge of the 3rd leaf down. This was one (the only ?) supplier for these spring assemblies.

Just 20 minutes ago, brushed off the grime on the 4th leaf down and there it is again. This is on a July '65 car. I believe the conclusion was that it's location is entirely random, with the roll stock that was fed into the cutting machine having this symbol every so often. Where it/they ended up on the spring assy was arbitrary.

[John H.]

Re: Another possible identifier: "GLS" forging

Wayne -

I believe that the "GLS" was embossed in the edge of the raw strip stock by the strip stock supplier (Great Lakes Steel) during its run through the rolling mill, not by the spring supplier (Ontario Steel Products or Rockwell).

[Gary B.]

GLS forging; not on most

Wayne,

I've examined and dismantled 5 or 6 original GM spring and I've only seen the embossed letters once, so I don't think most springs will show the embossing. The upturned ends is by far the easiest way to detect original GM from repro.

Gary

[john daly]

Re: GLS forging; not on most

If you have access to past Restorer magazines Gary has authored (co-authored ?) a couple of comprehensive articles on mid year leaf springs.

jd