I think the motor mounts are different on the LA blocks.

 

Or you can just carb the Magnum. Get a carb Airgap and distributor and just convert it. Rip the whole wire harness out of the truck, and start from scratch.

 

I carb'd a magnum engine I put in my Mazda pickup with a Hughes whiplash cam. You can get the knock off airgap for less than 150 off eBay.

 

The mounts for the la are on the magnum but the magnum mounts aren't on the la.

 

i think i read that the magnum engines have LA bolt holes but the LA blocks don't have magnum bolt hole so you would have to use the magnum block. i also think you would need to keep the computer to control the speedo, alternator and maybe other stuff. you might also want to swap to a hydraulic trans if you don't have one. you would also need older distributor, fuel pressure regulator, intake, Ignition Control Module and the know how on how to wire all this stuff in to work.

 

The 46rh I put in my Mazda uses a cable for the speedo and as far as the distributor goes every one I looked at is just a a one wire hook up like an hei chevy, just need a wire that's hot with the key on. As for the alternator the voltage is regulated by the computer, I had a armature shop install a regulator and one wire hook up like a older chevy.