Remove the 2 bolts on the portside of the front motor mount,... Then the spacer block will come out...
Remove the old belt,+ install the New 1,...
Then replace the spacer block,+ the bolts you removed...
And while you that far, install a second belt as a emergancy spare safely tied out of the way. This way you wont have to remove anything to chage the belt is it should break again.
i dont know if there is a difference between a 1978 and 1971 or not but i just changed my belt and went through the same steps but i still had to raise the motor up about 1/2 in. to allow for the belt to slide through the space between the housing and the motor mount.
Thanks for info, what kind of belt is it? Sometimes I can order parts a chevy but the one they give me dosen't fit. That sounds real easy, and that second belt. WOW great idea...