[dana44]

IT is actually a pretty straight forward swap. Engine, wiring harness, fuel lines and fuel tank pump should do it. Sure, there are a few hoses here and there, but it is overall a straight forward swap. Check the size/shape of the fuel tank, if it is the same, just the screw-off top and the guts/lines from it to the Lebaron to the Horizon will take care of that. Last thing would be verify the exhaust system is the same, which I believe it is, and you are done. The difference between the 2.2 and 2.5 is I think one inch taller block for the 2.5 (before the common block was designed)

 

[dana44]

Once you pull the computer wiring harness and the extra power box, trace the wiring back to the fuel tank, it is only two or three wires in a harness. If the Horizon is a manual fuel setup, pull the other tank, lines and purge lines, and tank, which should be the same or very close size and replace as a whole unit. Basically, replace the body around the car, and to that extent, someone else may be able to answer the question if it would be even easier and faster to unbolt the whole front engine cradle, struts, and steering/transmission linkage, and take the whole nine yards for an even quicker swap.

 

[dana44]

For the tank there may also be a screw-off top that can swap everything, but I don't think so, one has a carb, the other has a fuel pump in the tank, and the return line, etc., swap the tank after comparison. If it is the same physical tank, do the swap, if not, external fuel pump and a return line.

 

[dana44]

The only slight concern would be whether or not the throttle body is large enough so as not to run lean. The computer/O2 sensor may be able to overcome this issue, a comparison of a 2.2 and 2.5 throttle body injector size would be something to check and change if necessary, but that is minor.