Has anyone ever put an X300 engine in their XJ40?
 

I heard the X300 engine was based in the XJ40 engine and would fit in an XJ40.

Basically, and very briefly, YES, it will physically fit.

Engine management will be a challenge, but not impossible.

Power steer pump has different angle of the dangle, as far as hose connections at the pump is concerned.

Wiring, as in injection, ignition, engine management etc is totally different. The AJ16 EFI is Nippon Denso. The ignition is 6 individual coils that are ECU fired, no plug leads etc.

There will be a MYRIAD of "not quite the same" areas that will frustrate the hell out of you in my opinion.

As I said, do-able, but really not for me, buy an X300 and get the real deal.

a regular swap over here, drop a 300 engine in, use the 40 distrubutor and leads, whip out the coil packs, and run it on the same ECU's works on 3.6 and 4.0 Uk 40's so i see no reason why it would not work on a 3.2 or any other XJ6 engined car of any market spec

we have a number of supercharged XJS's over here too