64 A body Handling question

There our 2 schools of thought on springs. 1st School is stiff springs and modest sway bar sizes. The 2nd School is soft springs and bigger sway bars.

The soft springs are for rougher road conditions and the stiff springs are for smoother road conditions. I have done both before and all I can say is that "it depends" on local roads where you live and what selection of sizes you have available. For a Chevelle everything, for an A Barracuda not so much.

Addco bars are cheaper, but the brackets require some welding and work to fit better. Search for pictures and fixes before ordering. IMHO.
Shocks are tough for the front as far as fit and listed in catalogs. Rears are easy with more choices and pricing.