I was wondering if the injection system of a 360 Magnum can be retrofitted in a 360 LA and how complex it can be

 

First the mechanical bolt up of the intake, then the crank sensor tone ring on the flywheel will give you trouble. The balance is slightly different between the two, the other sensors that send data to the computer to adjust ignition timing/fuel mixture will give you lots of work. If you do manage all this you'll end up with a limited computer that can't be easily programmed to suit your needs. I would say, YES COMPLEX.

All these things is what has fueled the bolt on EFI aftermarket.

 

I would think the Magnum flex plate can be worked around.

The biggest stumble is going to be the intake. If you REALLY want to do this, one way would be to convert to Magnum heads, which can be done. Then your mag intake becomes a bolt on.

But otherwise you'll have to take a carb intake and put injector bungs in, then adapt all the hardware, sensors, etc, off the mag intake to the new LA intake.

This should be doable, depending on your skills and budget.

The PROBLEM with using all Mopar OEM ECU is that it's harder to change the tune, and if the donor computer is new enough to be a 'security' ECU for lack of better word, you'll have to pay to have it reflashed, so far as I know.

Another thing to check out is Megasquirt.