Front spring question

[mike343sharpstk]

I am designing some upgrades to my ’69 Javelin front suspension.
Long story short, these cars do not have an upper ball joint, as they used Trunion until 1970. At that time AMC switched to a front suspension similar to Mustangs of that same era.
When the trunion are well maintained they are fine, but have some drawbacks like limiting tire size and limited caster adjustments without binding.
Additionally the upper A-Arm locations do not have the typical anti-dive geometry. And the way the front suspension is set up I can’t just drill new holes in the chassis to move the location of the upper A-arm mount point.

There are very good solutions out there to replace the front suspension all together, and I would like to do that on my next build, however on this car I want to make it work using the factory suspension mount points and as many stock parts as possible.

Finally to my question: I am designing some modifications to the front suspension, and because I don’t have any anti-dive geometry can I get opinions from some experts if they think the use of dual rate or progressive springs would be something to consider for this application to manage dive?

I did an auto-cross this summer and the car worked great, but the front of the car did dive a fair amount on hard braking.

In a past life I raced motorcycles, and I used a progressive front spring for a short time, and it just didn’t work as well as a properly set up linear spring.