Roller cam - Magnum

The two '89 318s are LA roller motors. The last year for the LA 318 was 1991, after that they were replaced by the 5.2 Magnums. The last year for LA 360 was 1992, after that they used the 5.9 Magnum.
In their original configuration, the easy at-a-glance ways to tell are:
1.) LA rollers have TBI injection manifolds, Magnums have the "beer keg" EFI manifold (Okay, there were some early 318 rollers that had 2 bbl. feedback carbs in Fifth Avenues and the like, but the majority were truck TBIs).
2.) Count the valve cover bolts per side. 5=LA, 10=Magnum.
3.) Motor mount bosses: LAs had the typical "ear mount" bosses at the front of the block. Magnums had the ears and mid-block flat mounting lugs.
4.) Serpentine accessory drive=Magnum. V-belts=LA.
There's lots of other little differences, but if you're walking past a stack of motors in the boneyard or looking at blurry pics on CL/Marketplace, this will tell you at a glance.