All,
I have the Detroit Eaton coil springs on the way. According to Eaton Detroit springs,
Ford 1973 Mustang Hardtop with 302-V8 and A/C
MC-3718 - Improved handling coil spring, 1 inch lowered, -spring rate-362 lbs
MC-1280 - Standard coil spring, - spring rate -295 .lbs
I currently have the 620 .lbs 1 inch lowered coils. As with comments from Mister 4x4, I agree. The 620's are too stiff.
As I have always pointed to Handling information, professionals have always recommended to replace your springs with the factory rates. Since the springs are what hold you car up. The sway bars prevent body roll. If you want to lowered, get the lowering type springs. The spring rate will determine the how it will ride!!
Recommended read-
How to Make Your Car Handle Paperback – January 1, 1987
by Fred Puhn (Author)
mustang7173