HQ chassis number meaning

[wbute]

You could always fit a 350 into HQ in NSW as far as I was aware. Later series you pretty much need to run them on gas and get an engineers certificate. Not sure how much this has changed now though. There seems to be lots of later LS1 conversions these days though.

[Dick61]

The first letter indicates the ADR update. The second two letters indicate the series. So HQ as there is no HO Holden. D would be late in the series. Possibly 74.

DHQ would be 73, most 74's were EHQ

[Dick61]

Sadly, in Vic anyways, you couldnt put a small block chev without engineers cert. The commercial line was never optioned with 350s, only sedans, wagons & coupes. I have already gone through all the channels to find that out, so after frustration, i decided on big block.....and even then, laws have changed where 400ci is the max theyll allow, unless youre prepared for some chassis bracing mods ie...braces, lower wishbone plates, tailshaft loops, trans cross member strengtheneing, then you could get lucky and pass 454ci. A 502 or 572 BBC wont even get a look in.......the laws have changed, but only because of cowboys doing dodgies over the years.
Im not sure what its like in NSW, but from what i understand, Vic is more relaxed when doing engineers cert.

I don't know who you have been talking to Ivan, but the NCOPs don't stipulate body style but model. I have been through the same information gathering as I want to put a 350 in my HQ ute and have been told that it is totally legal. If the engine was an option on that model then it is legal, whoever has told you that it isn't doesn't understand the regs or the NCOPs which Vicroads have signed off on.

[wbute]

I bElieve the HQ Ewe't had a 350 from the factory so you can argue it was an option any way. Bob Jane got them in station wagons as well. I really think the ruling about body style could be debated.

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DHQ would be 73, most 74's were EHQ

I had this conversation with Byron before. The letter changed with the ADR update. No real correlation with the year.

[Alien DNA]

I'll be able to confirm all the specifics next week as im taking a break for a week off work, and getting back in touch with the engineer when i get back. Spoke today briefly to him and VicRoads have implimented another rule that goes by vehicle weight to measure max cubic inches. Power becomes irrelavant now, which has always been a sticking point for engineers.
eg- previously laws satated that the max cubes for a HQ was 400ci.....new rule formula says 427 is possible. One engineer i spoke to said he could pass 454ci if i did a bunch of chassis and suspension mods. this rang alarm bells for me because if i went for a 396ci BBC, because off the smaller cubes, i wouldnt need chassis and suspenion mods,....but the engine weight would be virtually the same. There are way too many grey areas between engineers.....but until i can get the law in black and white, i dont believe what i hear or see.

[Dick61]

I bElieve the HQ Ewe't had a 350 from the factory so you can argue it was an option any way. Bob Jane got them in station wagons as well. I really think the ruling about body style could be debated.

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I had this conversation with Byron before. The letter changed with the ADR update. No real correlation with the year.

I do know how the prefix letters are tied to the ADR upgrades but the fact is that in HQs AHQ and BHQ were 1971 to early 1972, CHQ was mainly 1972, DHQ was mainly 1973 and EHQ was mainly 1974, it wasn't based on the year but the way that ADRs were introduced panned out that way.

[wbute]

The year of the car isn't a calendar year either. I think it's September when they change over or close to. So it's either 73 or 74.

[Dick61]

I'll be able to confirm all the specifics next week as im taking a break for a week off work, and getting back in touch with the engineer when i get back. Spoke today briefly to him and VicRoads have implimented another rule that goes by vehicle weight to measure max cubic inches. Power becomes irrelavant now, which has always been a sticking point for engineers.
eg- previously laws satated that the max cubes for a HQ was 400ci.....new rule formula says 427 is possible. One engineer i spoke to said he could pass 454ci if i did a bunch of chassis and suspension mods. this rang alarm bells for me because if i went for a 396ci BBC, because off the smaller cubes, i wouldnt need chassis and suspenion mods,....but the engine weight would be virtually the same. There are way too many grey areas between engineers.....but until i can get the law in black and white, i dont believe what i hear or see.

If you get a copy of VSB14 it sets out the NCOPs which are what Vicroads have signed off on, you will see that there has always been a weight to cubic capacity formula which uses the unladen weight of the heaviest sedan version of the model in question to calculate the cubic capacity in ccs. This in an HQ worked out to be 451 cubic inches, so yes the 427 is the largest allowed in an HQ. If your engineer has only just "discovered" this I think you need to look for someone with a better understanding of the regulations.
https://infrastructure.gov.au/roads/.../vsb_ncop.aspx

Here is the link to the Dept of Transport site and has all the NCOPs in the form of VSB14 which has about 20 parts. I have been studying these and the 2nd and 3rd generation ADRs since starting the build of my ICV motorbike in 2007

[Dick61]

The year of the car isn't a calendar year either. I think it's September when they change over or close to. So it's either 73 or 74.

As in the original post, the chassis number of DHQ 8XXX5S would be a 1973 built 1973 model.
The ADR plate from my 7/73 HQ prem wagon reads DHQ 91859M unfortunately I can't get the picture of the tag to load.

[Innuendo]

September is the model year change point. So 10th Month is the new model with Holden and 9th month the last of the previous. I.E: 9th month 1974 is a HQ 10th month 1974 is a HJ this is true in "most" cases. Sometimes certain commercial model Holden's would carry pass the date. Although not in HQ-WB.

ADR updates are the reason for the letter prefix change in chassis numbers. That's not to say when a ADR is introduced but from when it is introduced to that model. Holden would sometimes introduce the change before the fact in preparation.