The difference between a plug-in loom and a standalone is quite significant.  

The plug-in loom is designed to "plug in" to the vehicle that the new engine is fitted to and utilise the fuse/relays box to the best of its ability. An example would be a VN-VS LS1 Plug-in loom.

The standalone loom is a "universal" loom which comes with its own relays and fuses and needs to be wired into the vehicle. It can be fitted to any vehicle and is generally used for cars that weren't fitted with fuel injection etc from factory so requires more fuses and relays for control.

LS2.  A common call that is received is from customers chasing a loom for the "LS2". A LS2 engine is a specific engine designation and although it is a 6L, not all 6L's are LS2's.

Now why is this important? A LS2 is a specific engine and can come in both 24x reluctor (VZ HSV) or 58x reluctor (VE HSV). The earlier 24x runs an E40 ECU to begin with and both LS2's run different heads, and intake manifolds and to be calling an engine you have a LS2 when in fact it could be a L98, L76, L77 and so on could lead to the incorrect purchase of part, and be an expensive exercise.
VZ 5.7L cars going into Limp, power reduced mode is quite common and is often more than likely caused by a failing pedal. These pedals are getting harder to find in working condition and are fetching a large some of money these days as people understand their rarity.

The pedals although coming in different part numbers are easily identified by the "Blue" sticker on the sensor section. The rest of the VZ range ran the same looking pedal but the sticker on the sensor is "White". The sensor works differently and therefore the pedals can't be interchanged between the V6/6L VZ's and the 5.7L VZ's.

With so many calls on this and finally getting the time Ultimate Conversion Wiring have come up with a solution. You can purchase a Module that allows you to run the V6 and 6L pedals out of the VZ's along with also being able to run both VE and VF V6 and 6L pedals.

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