Spring rates to start with.

[Thomas Wirtz]

I'm restoring a 1978 Argo JM2 Super Vee and I want to replace the 40+ year old springs.
I just found the original setup sheet from ARGO that came with the car stating that
275 lbs springs should be used in the front and 300 lbs springs in the rear.
The car presently has 375 lbs springs in the front and 425 lbs spring in the rear.
Any thought or suggestions on where to start would be appreciated.
Thanks Tom

[Steve Demeter]

I will give Tom Pomeroy a shout. He had great success with a JM2 in the day. Maybe he remembers

[Daryl DeArman]

Your spring rate ratios are very close to what Argo suggested back in the day.

For example 550/600 would provide the same F:R spring rate ratios as the 275/300, it would just be twice as stiff.

With a 375F you would need a 409R spring rate to be at the same ratio. Alternatively with a 425R, you would need a 390F. Tires have changed a bunch over the years. I'd stick with the the 375/425 set up you have now and see how you like it before you change things only to end up right where you started.

[Steve Demeter]

Heard from Tom.

He does not remember spring rates. But did say to run it as low as you can get it without destroying the tub. He won a lot of races with that Argo both Air and water cooled.

[Daryl DeArman]

Heard from Tom.

He does not remember spring rates. But did say to run it as low as you can get it without destroying the tub. He won a lot of races with that Argo both Air and water cooled.

"It" as low, as in ride height or spring rate?

[Thomas Wirtz]

Thanks Steve and Daryl,
I appreciate your input.
I'll start with new 375/425 springs and a lower ride height and see how the car performs.

[Steve Demeter]

Low as in ride height