Serpintine belt setup

If you want to use the serpintine belt system on a non serpintine belt engine, there is an issue with the timing cover being to thick. This is due to the cam snout on the older engines being longer than the roller cam Magnum engines.
Also accer. holes in the head are different on "LA" vs. Magnum heads.

With Magnum heads up top and a "LA" timing cover;

If your crafty, you can space out the brackets. This will take some brian matter to do since this is not just a simple idea of useing longer bolts and hollow tubes to move everything foward. The A/C compressor may still bolt to the intake. I'm not totally sure how that item is mounted up top.

You can not use the magnum's thinner timing cover on a "LA" engine because of the cam snout being longer. If you swap to a Magnum short snout cam and use the Magnums thinner cover, you then have a fuel pump issue since theres no place to mount a mechanical pump in the thinner Magnum cover. You'll need a electric fuel pump.