Hi Ramy,
My SU manual covers Volvos from '63 to '74, but doesn't list the PRV V6
2.8
litre. This engine was introduced to the Volvo line on October 03 1974.
Perhaps that's why the PRV is not listed in my SU manual! Tim has pointed
out that the early PRV's were equipped with twin Strombergs, not SU's.
Maybe you have a Stromberg.
Have a look at this:
http://www.autozone.com/servlet/UiB..._us/0900823d/80/1d/8c/92/0900823d801d8c92.jsp
BTW, "The Carb Came Back!" (in single form) for 4-cyl. models in '77, and
continued 'til '84 along with F.I., at least in Canada.