The 71-74 B body rearends are actually wider so you want to make sure what you are getting. 62 through 70 B body flange to flange are about 55" while the later ones are about 57-3/4", all E bodies are 56-1/2". The spring purches on the early B is 55" while the E body purches are at 46". Get some measurements and you can see what you are dealing with.