In your original post did you mean difference between 360LA & 5.9 magnum? The advantage to the magnum is that it has roller lifters, not worrying about zinc additive in the oil. Disadvantage is intakes are different and maybe a few other things like serpentine belt for water pump, power steering pump and water pump. You have to decide what's best for you.
Ok. But is the bolt pattern on the front of the 5.9 the same as the 360? This would include the bolt holes in the heads If so then I could use everything on the front of my 273 including timing cover, p/s and water pumps and alternator brackets?
