Craig, let me take a stab at something. You and I both think alike. We like to see quantitative data and formulas to back up the things we observe in the real world. I assumed you were looking for a way to back up what Fred is describing. Funny thing is, the same thought went thru my head but I didn't know where to start. When you prompted me to google spring frequency much to my amazement there was actually something out there. You farm for a living? Oh my! You have my utmost respect! Things aren't what they used to be.

By the way, the 'sprung weights' I used were 13 ounces on the front corners & 21 ounces on the rear. I also found moving the lower shock mount location increases the spring frequency by about 10%. Do you have a way to measure your springs? Years ago I used a drill press to compress springs on a scale. Rather crude, but I only wanted to match left & right.

Fred, I agree with you on laying the shock over at the tower. My information came from the first source I google'd. Obviously there is an error someplace. I will keep searching. Maybe it's the way the formulas were put into Excel.