aspen station wagon upgrades
I recall taking a test drive in a new Volare wagon when the Super Six first came out. I thought it had a 318 by the way it performed. A properly tuned slant with the right gearing is a decent performer, so I agree that a gear change will give you the most bang for the buck.
My '64 Valiant has that setup and I have no complaints about performance, but then I don't expect it to be a race car.