I have a 1981 bronco with a 351W. It came stock with a the two barrel Variable Venturi which was later replaced with a two barrel Holley carb. Holley no longer makes this carb or a rebuild kit for it. Due to this I have decided to install a four barrel ford manifold and a four barrel 600 cfm Holley carb. I figure this will work better since the 351W sucks way to much of a vacuum for a two barrel anyway. What I was wondering is where can I find schematics to compare the vacuum flow and emmissions flow for these two years 1981 and 1984? Can anyone help me figure this out please? Any information any person has would be helpful. In advance thanks.

 

Perhaps you can just use factory parts from a junk yard, my 86 is the 351, but with a 4 barrel already.