Hey folks,

I've got an XK Falcon with the driveline out of a '67 Mustang, with a 289 Windsor and a reconditioned C4 auto.
The old 289 currently runs rough, is low on power and thirsty on fuel, even though it's been tuned properly. It could use a good rebuild, but I've been entertaining the thought of just disposing of it and replacing it with a 220kw AU XR8 engine that seems to be not too expensive and plentiful. Given that they're both Windsor engines, I'm hoping that this will be a relatively straightforward swap.

What seems to be needed, as far as I can tell, is a high-psi inline fuel pump, a return line through the sender, an o2 sensor in the exhaust pipe, and obviously a 5.0 with all accessories and electronics attached.

I have a couple of questions:
- Will the modern 5.0 bolt straight up to the old C4? The gearbox works perfectly and I'd rather keep it and the driveshaft.
- Would it be fine to straightforwardly transplant all the electronic gadgets from the donor AU into the XK? Having never owned any EFI cars I'm a little daunted by this. Is it possible to pull the harness and related computers out of the AU, just feed it power, and go?

I appreciate any help on the matter - and if anyone who's done similar things can point out any potential problems, please let me know.
Thanks!

sounds to me that the carb is not tuned and jetted correctly as the 289 windsor was always known for being an efficient engine.

This isn't the case - I've had the engine professionally tuned and looked at by two respectable mechanics, and yet it only produces 138rwhp on the dyno.

The diagnosis was that it seems to have been poorly reconditioned in the past and the internals are worn, and to get it back to a reasonable level of power it has to be pulled apart anyways, hence considering the engine swap.

have you thought about 351 windsor then, alot more torque than 302/5L.

I cant see there being any issues. My mates mustang 347 runs an AU block, then all the carb etc from his old 302 block .

351 Windsor will be a lot harder to fit in an XK due to the extra deck height.
The gearbox will bolt up to the AU motor and the flexplate will bolt to the motor but will be the incorrect imbalance. It will need to be rebalanced.
Fitting the AU wiring and ECU can be done but you would be better off running it as an EB ED setup and using the plug and play wiring harness available from RJM Injection tech.
I run one in my Maverick and can highly recommend it.

Perhaps a carby could be a simpler solution?

Yep it's doable. It will bolt up and if you use the entire AU harness it will work. If you do it without using the whole harness and just use the engine control harness you'll need to turn off smart shield which is also doable by a couple of methods.

Thanks for the reply guys,

Given what I've heard so far I'm going to seriously start researching into this. What's the best workshop manual to refer to for finding out how everything is set up on the AU XR8 with regards to all the wiring and accessories? I'm leaning towards using a 100% stock AU setup, for ease of setup and maintenance.

Also, who can rebalance a flexplate in Sydney?

Cheers!

Just buy a 157T 50oz flexplate from Scat....fixed. That's assuming you have a small bell C4?...should be if it's from a 60's Stang.