VSB14, vehicle standards bulletin 14 or the NCOP (National code of practice) is the document referred to when performing vehicle modifications. VSB14 is broken down into a number of sections. Each section dealing with a major element of the vehicle.
Sub section 1 of whichever section of VSB14 you are reading includes the scope, basic modifications not requiring certification, modifications requiring certification and in some cases modifications not covered.
In section LS (suspension) some of the basic modifications listed are changing shocks, springs and sway bars or adding a strut brace. Even with the listed basic modifications there are conditions and limitations. A condition is set for the amount of ride height change that can be performed without certification. Then within the certification section a maximum and minimum ride height is specified. Adding to the complexity within the certification section is the checklist of the mandatory items required.
As an example of recommend vs mandatory, table LA1 Recommended maximum engine capacity provides a method of calculating the recommend maximum engine capacity. As noted in the table title, this is a recommendation.

Modifications not covered by a section of VSB14 does not necessary mean the modification can not be performed. Any modification outside the scope of VSB14 will require specific approval to be granted. In a number of cases VSB14 gets interesting where features OEM’s are including on vehicles can be installed however aftermarket versions of the same modification type cannot. VSB14 states in section LS “Installation of Variable Air or Hydraulic Suspension Systems: Installation of non-original suspension systems that allow the ride-height of the vehicle to be varied by the driver are not covered under this Code of Practice.” Likely the reasoning behind this is due to the amount of testing OEM’s perform and the safety constraints they are able to include. Constraints like the rate of change in height of the suspension system. In comparison Lowriders with hydraulic aftermarket suspension experience bouncy height changes and what seems to be frequent suspension failures. This is an observation and in no way am I claiming to be an expert on Low rider suspension systems.

Sub section 2 covers general requirements.
This sub section is an overview setting expectation of the modification. Fabrication techniques, strength of mountings, clearances and any related vehicle systems that maybe impacted by the planned modification.
Installing a performance engine that is wider, weighs less and more powerful than the original, general requirements will list items to consider like:
• Engine mounts, these will need to consider the addition power / torque the engine will have.
• Clearances, there are minimum clearance requirements which need to be considered as the engine being used is wider than the original.
• Exhaust system, clearance, heat and noise emissions.
• Suspension, the selected engine weights less than the original is positioned in a slightly different location. The impact of the handling performance has to be considered.
• Fabrication, all fabrication must be to standard.

Sub section 3 looks at potential ADRs (Australian design rules) being impacted by the modification.
Some of this is very basic, some not so much. A replacement engine must have the original emission control equipment installed. The same replacement engine must meet or exceed the ADRs that the vehicle was built to. IE a 2015 engine into a 1990 production vehicle is no issue. A 1990 engine into s 2015 production vehicle will not pass. In some instances vehicle testing is required to confirm the replacement or modified engine passes the emission standards.
Let’s say you want to install a 2JZ GTE engine into a 1995 Hilux. Clearance and everything looks good. Where things get interesting is the 2JZ GE the non turbo engine was emission complied with ADR but the 2JZ GTE (turbo motor) did not get released in a vehicle by an OEM in Australian. It was only in Grey imports. The 2JZ GTE will have to be emission tested to confirm it complies with the relevant ADRs. Some states do not require emission testing on engines or engine modifications where emission equipment is installed, but the 2JZ GTE was never proved to be ADR emission compliant therefore requires testing or proof it passes the standard at least equivalent to the standard of the original engine installed in the vehicle when being used as a replacement engine.

Sub section 4 provides a more detailed look at basic modifications not needing certification.
“Substituting the original engine with a manufacturer’s optional engine is a modification that does not require certification. However, any other components (such as brakes, transmissions, suspension, exhaust, etc.) that were packaged by the manufacturer as part of the original specification for the optional engine must also be fitted.”
As examples:
• Swapping a V8 into a vehicle that originally had a V6 and the V8 was a factory option.
• Installing a turbo changer to a vehicle that had a turbo charger as an option.
Or
“Replacement shock absorbers (including struts and strut inserts) may be used provided that they have been manufactured as replacement units for the particular vehicle model and have compatible mountings and dimensions.”
One question that gets asked often:
Do I need a mod plate when installing coil overs? In most cases no. Most coil overs use the same mounting points and have compatible dimensions.

Sub section 5, this sub section lists all the codes for the possible modifications. The scope of these codes (what is covered and what is not) and what ADR maybe affected. A checklist is included detailing the required inspections.

This is a basic overview of VSB14. Each section of VSB14 is anywhere between 70 and 150 pages of information. It is a large amount of information to filter and apply to any vehicle modification. As a big plus anyone can download VSB14 and the ADRs and have a look.