The 351 and 302 speed density uses bank firing for the injectors, 1,4,5,8 then 2,3,6,7. The 302 has an anti knock sensor where the 351 does not have a provision for this sensor. The firing order is controlled by the distributor. If you were adding mass air to the truck then you would have to worry about appropriate firing order of the injectors. To be on the safe side it is best to use a 351 computer, but I believe it has been stated that both engines use the same injectors. I have seen the opinion swing against the M5OD mated to a 351 as it may not handle the torque, but that just depends on your driving style too.