P5153590 Fuel Injection Kit Install

"Why couldn't this be used a 318 with the HP range?"

The intake manifold in this kit is specific to the Magnum small block; and then the injectors rails are specific to that manifold. So you'd have to source an LA 318 intake with injector bosses and the fuel rails to go with it.

Semi correct. The kit was developed out of house by a magazine (I forget which one, MoPar Action I think,) for the 360/380 create engine.
It has a computer with it and is so mapped for that engine specifically. Use on a 318 would probably have it running rich on the low end since torque production is lower.

The 360 & the 318 Magnum engines use the same exact manifold and would also use the same frame rails. The injector size would probably remain the same as it is a HP dependent issue more than cubic inch. Adding injector bungs to an "LA" intake is the way to go. Getting a intake with injector bosses (specifically) is as far as I know impossible.

The computer would have to be messed with to fix the issue.