What if : Linebacker III circa 1980

Greetings everyone
I know this may sound stupid from the historical point of view but imagine if in Indo-china another crisis developed in 1980 and US got involved
only as far a aerial bombartment is concerned with B-52s F-111 flying strikes
escorted by F-15s and F-4s
against an soviet developed Vietnamese airdefence system with the latest SAMs , Su-15s MiG-25s as interceptors and MiG-21s and MiG-23s as fighters
Now leaving aside political considerations how do you expect the attacks to fare?
And if you are the viet commander what kind of tactics will you use considering the assests avaliable to you to inflict the max. attrition on the US airfleet?