This is the set of UPPER and LOWER insulators for 64-72  mainly Chevelle, some Malibu, El Camino, some LeMans etc.. look at what these are.. 

   Usually for 350 Chev etc. .or 2 or 3 core radiators.

This set has ONE prong on each as shown.

This is a set of 4.
 

  This set  is 2.5 inches wide on the inner arch -  you get two upper and two lowers.    (The 4 core is - 3.1/8 inches wide)