The aftermarket tubes are too long (the EMPI one is fine - there, I've said it), presumably to accommodate different engines. You do need to saw a bit of the end, so you've got say a centimetre stickout from the tinware grommet. Then the flexi-conduit will seat properly. Too long, and the flexi will be cocked where it meets the tube, and you may have probs with accelerator cable length. In theory, if the tinware/shroud grommets are tight and grease-free, the tube should stay put...but they never do. They have a deep desire to go walkies. Either put a hose clamp or large cable tie behind the fan shroud or, as I did, make a small plate to go on the shroud facing you that clamps the whole thing in place.
Fix update! Luckily not an engine out job, but the cable sheath which runs over the gear box was not sat in right. It needed to be push into and towards the engine. I only found this out by wiggling it in. Hey presto.
