Application
To determine which spring clamp will fit your application you would need to measure the width of your leaf spring. Using a tape measure, ruler or caliper, simply measure the width of your main spring leaf (not length of leaf or leaf thickness) and order the spring clamps for that width.
1-3/4" was the standard width spring for most early coupes and roadsters (and aftermarket uses this spring width for nearly all of the universal front end kits). Some later fat fendered Fords used the 2" wide springs in front. The 2-1/4" wide springs were normally found on the rear of early Fords.