You have to be aware that the early set-ups before the OHC3.9/4.0's were
'brain dead'
cast offs of BMW 323i technology.
No EPROMS.
None had a 3-way cat or feedback systems like the later ones had.
Jack Collins said its much better replaced with a SDS system, and get rid of the horrible air vane meter.
It's not entirely dreadfull, but its only a good thing if you can get the stock system easily.
The stock XE and XF EFI set-up can be hard on fuel if not set-up correctly. It does have globs of snatch free low-end grunt quite unlike most 4-bbls. thats 240 lb-ft, better than an 83 5.0 GT 2-BBL. It's like a good EFI 302 for low end torque, but runs out of grunt rapidly past 4000 rpm.
The XE EFI swap is so easy its funny. Cam is the same, the compression is 8.8:1 via a differntly machined chamber, but if you run US 93 octane grade, the 9.35:1 copmpression won't cause problems.
The stock ECM is wired seperately from the factory. The stock pump is hung off the steel gas tank on the wagons and utes, and its very easy to us the stock aftermarket return line or still pot kits the 5.0 EFI guys use. The air box fits where Jack and his son have there's in the Crossflow Chronicles 66 Mustang. The stock reinforced rubber gooseneck doesn't fit the engine bay as well as the Aussie Falcon. The early American Mustangs and Falcons have heaps less space to each spring tower. The pressure regulator and basic gear is easier to get as a junked EFI engine than pay on each part. No different here as it is in most junk parts in the states.
The worst issue is the later XF engines. They are high swirl, and you don't dare swap a carby 4.1 to EFI unless you use all the right bits. The EFI runs a wilder cam, and very different chamber machining. There are some early leaded carby 4.1's which have 9.35:1 compression and are desiged for your 93octane. Herein lies a problem for low grade gas users:-
If you put later unleaded EFI system on 4.1 carb leaded engine, and run it on your 87, it'll ping it s head off. With or without the knock sensor
XF engines are great if kept stock, but you must reduce the compression ratio or go to 93 octane for safety's sake. If you run the same SDS system as Jacks XF engine, then it should be fine, as its a whole lot smarter.
The XF EFI has heaps more power at 162 hp, verses the 149 of the XE efi. There is 246 lb-ft on the XF, and 240 on the XE EFI
The carb 4.1 has the same factory 131 hp (it was rated at 141 earlier, but was never actually dynoed at that level). stock torque was about 229 lb-ft.
The SDS system elimates the air vane, and gives a great performance boost. mustangsix2's device must have 200 hp just as it stands with the better cam and headers.
