FOR THE LEAST AMOUNT OF WORK , A 92 THRU 95 DOHC WILL BOLT RIGHT IN AND WORK JUST FINE , JUST FINISHED ONE ON MY SONS TRUCK, AL YOU HAVE TO DO IS US THE ENTIRE TOP MANIFOLD ING FROM THE SOHC AND ALL THE PLUMBING AND EVERYTHING BOLTS RIGHT UP , SO YOU END UP WITH A DOHC WITH A SOHC INTAKE SYSTEM , AND THEY RUN GREAT I HAVE CHANGED 3 OF THEM OVER AND NO PROBLEMS THE ECM DOSEN,T KNOW THE DIFF, JERRY