Throttle return and kickdown springs

Glad I stumbled upon this thread. Is there suppose to be a significant response between the spring and transmission linkage? My stock spring is a bit worn out I think. To describe it, my automatic transmission (‘74 225 with the 1920) is shifting hard from 1 to 2 at nearly 30mph, revving serious RPMs, then from 2 to 3 at nearly 50mph with the same response. Once I hit 3rd, it immediately wants to hop back to 2nd at nearly 50. Surely my spring isn’t the main cause? Perhaps a linkage issue?