C2 Rear Spring Help

[Mark P.]

I got this spring as one of the spare parts when I got my 1965.

Does this look like a NOS F40 spring or a repro ? A friend said it kind of looked like his F40 spring but should not have the plate on the bottom of the 7th leaf.

[Mike M.]

Re: C2 Rear Spring Help

show a close-up of the ends of all the spring leafs.mike

[Mark P.]

Re: C2 Rear Spring Help

Does this help ?

[Mark P.]

Re: C2 Rear Spring Help

One more photo....

[Mike M.]

Re: C2 Rear Spring Help

flaring of the ends of all the secondary leafs is common to original c-2 and i believe c-3 springs . i've not seen any aftermarket leafs with the flaring feature so i'd say you have original vette spring. mike

[Gary B.]

C2 Rear Spring; My guess is repro

Mark,

From 1975 thru 1979 the HD spring came with a flat top plate like on your spring. Can you measure the thickness of the top plate? For 1975-1977 it should be 0.306". For 1978-1979 it should be 0.225".

The stenciled number on the spring is not a GM part number. My guess is the number is the code from the Spring Research Institute and this would suggest the spring is a repro. Also, are the angle cuts on the ends of the main leaf at 45 degrees? If not, that would also suggest it's a repro.

Having said that, the end treatment on leaves 2 thru 7 looks very close to the GM style.

Gary

[Mark P.]

Re: C2 Rear Spring Help

Hello Gary. Its .295 so this looks like a 75-77 spring, right ? The ends are at 45 degrees. Could it be NOS ?

[Gary B.]

Re: C2 Rear Spring Help

Mark,

NOS? Don't know for certain, but the non-GM number suggests otherwise.

Gary

[Bill M.]

Re: C2 Rear Spring Help

This looks identical to the 7-leaf 370350 I bought from Chevy in 1979. Mine has the thicker plate. (I painted the spring in 1979; don't remember if there was a part. no. on it.)

[Patrick H.]

Re: C2 Rear Spring; My guess is repro

Mark,

From 1975 thru 1979 the HD spring came with a flat top plate like on your spring. Can you measure the thickness of the top plate? For 1975-1977 it should be 0.306". For 1978-1979 it should be 0.225".

The stenciled number on the spring is not a GM part number. My guess is the number is the code from the Spring Research Institute and this would suggest the spring is a repro. Also, are the angle cuts on the ends of the main leaf at 45 degrees? If not, that would also suggest it's a repro.

Having said that, the end treatment on leaves 2 thru 7 looks very close to the GM style.

Gary

I would agree with your comment regarding the ends of the bottom leaf not appearing to be cut at 45 degrees from centerline.

I would also note that the liners do not appear to be the typical "H" shape that came on GM springs. These do not appear to have any "end" to the "H" - just a flat piece of plastic.

Patrick

[John H.]

Re: C2 Rear Spring Help

Mark -

Is there a remnant of a stenciled "JRS" on it anywhere? John R. Spring Service in Warren, Michigan has been the primary manufacturer of the reproduction 7-leaf HD spring for many years.

[Gary B.]

NOS? Sort of...

Mark,

My guess is your spring is an NOS spring. I just don't think it's a GM NOS spring. Having said that, the ends look to be the correct tapered rolled style, so the spring would be close to the value of a GM NOS spring, which is to say, of significant value to someone who knows his or her spring geometry. My guess is the spring is an old NOS spring, made by someone back in the 70's who knew how to do it right, such as JR Spring, as John mentioned. The current repro springs are not very close in terms of the end treatment on leaves 2 thru 7.

Gary

[Mark P.]

Re: C2 Rear Spring Help

The leafs are all 2 1/4" wide.

Here are the lengths for the leafs.
49", 42", 36", 30", 23", 17", 11" and the piece that bolts on the bottom is 7".

Does this make it any clearer what this spring was for ?

[Gary B.]

Leaf width

I think 2.25" wide applies to 63-77, after which the width increased to 2.50".

Gary

[John H.]

Re: Leaf width

I think 2.25" wide applies to 63-77, after which the width increased to 2.50".

Gary

Yup, you're correct - fat-finger typo on my part; deleted my previous post.