64 Skylark and leaf springs!? but I digress, welcome to the board as an "engineer" I would think that a quick analysis of what is needed to improve upon a system would be the first place to start, understanding how suspension geometry changes as it operates affects the loads placed on the tires, knowing this will tell you what it tacks to achieve you goals how ever loafty those may be, btw goals and $ have a VERY close tie
So a nice set of modern tires will improve the handling feel but will transfer more load to the suspension and chassis now you need a better suspension...it's a never ending quest ultimatly the driver is the limiting factor.