This photo may add a little bit of clarity...
RADIUS ROD BOLTS
Commonly referred to as “perch bolts” there were three different designs utilized.
A pair (left in photo) of bolts (78-3032) was used on V8 models that were not equipped with a ride stabilizer. One right (01A-3032-A) and one left (01A-3033-A) were utilized with the first design ride stabilizer assembly (center of photo). Each had a grease fitting. These had a 5/8” diameter bushing hole. Released for immediate use on January 14, 1940, redesigned and renumbered right (01A-3032-B) and left (01A-3033-B) had a ¾” diameter bushing hole.
Lastly, renumbered right (01A-3032-C) and left (01A-3033-C) and redesigned (right of photo) to accept the later and final design of ride stabilizer assembly, these bolts were released for immediate use in mid December, 1939..
A special slotted nut (B-3036) and plain steel cotter pin (72035-S) held each bolt in place