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85 VK 6cyl to V8 conversion questions

Marco308

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Hey guys I have found a very clean and tidy original VK 3.3L thinking about buying it as a project. Just wondering what's involved with 6 to V8 conversion and roughly the costs?

I'm happy to run it with the original motor for a while, but would definitely want to put a V8 in at some point. What V8 would be best fit for this model?? Would prefer a carby 253 or 308 but would also maybe consider the injected 304.

Thanks for any advice.
Cheers
 
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vc commodore

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Costs? Cost of the motor varies.....You could go 304, with a carby conversion (roughly $900 for manifold and carb), or 253/308 carb version...Either way a carbed motor would be cheaper to install, if you aren't handy with car electrics...

You'll need a V8 accelerator cable....K-frame and gearbox cross member are the same....Diff....If you are going 304 or 308, a disc braked rear is a must, as that's what was fitted from the factory....Last disc braked rear I bought set me back $150, but I stole it at that price...Not sure with the VK's whether you need tailshaft modifications, converting to a disc braked rear.....Last cut and re-balance of a tailshaft I had done was $200, but that was 9 or 10 years ago...

Do you want power steer? Is it fitted...No idea on price with that....Then the spring upgrade, to cope with the weight of the 8 up front......Last set of lowered springs I bought cost me $80 for the set.....Again, stole them at that price....

Conversion wise....The 8 will drop straight in, along with the gearbox.....Can be done in a day, or 2 depending how mechanically minded you are....It's the rest of the things that take a little time
 

Marco308

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Thanks for the advice. The list of things that need sorting out don't seem too bad. I'd rather not mess around with electrics and carb/ manifold conversion required with the injected 304 unless it really is the better option....

Does anyone know if there are any regulations stopping you replacing your original motor with an older year motor? Say dropping a 83 VH 253/308 motor into a 1985 model VK?

Thanks
 

gtrboyy

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253 was cancelled when vk model came about replaced with efi 202 option.
Hate to say it but was an improvement.

Conversion is practically bolt in job...downside is if you have to pay for labour & donor vehicle is easiest way.

For carby 3.3 not that hard to mod/extend wiring harness to suit v8,also if use 308/trimatic the 6cyl tailshaft/diff etc all bolts up to make it drivable
10-20 different ways to do the conversion + parts choices so cant price it honestly.

I've found injected conversions cheaper mainly easier parts availbility of a donor vehicle also 'cos I'm the sucker doing all the labour & usually when buy old carby car everything usually needs to be reconditioned or replaced,broken or missing.

Holdens getting that old seems less knowledge out about them helps get away using efi block in old car no pollution gear or old red block in newer efi car.

RTA wouldn't have a clue if it's not on their computer,cars were built before most if them born lol.
 
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Marco308

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253 was cancelled when vk model came about replaced with efi 202 option.
Hate to say it but was an improvement.

Conversion is practically bolt in job...downside is if you have to pay for labour & donor vehicle is easiest way.

For carby 3.3 not that hard to mod/extend wiring harness to suit v8,also if use 308/trimatic the 6cyl tailshaft/diff etc all bolts up to make it drivable
10-20 different ways to do the conversion + parts choices so cant price it honestly.

I've found injected conversions cheaper mainly easier parts availbility of a donor vehicle also 'cos I'm the sucker doing all the labour & usually when buy old carby car everything usually needs to be reconditioned or replaced,broken or missing.

Holdens getting that old seems less knowledge out about them helps get away using efi block in old car no pollution gear or old red block in newer efi car.

RTA wouldn't have a clue if it's not on their computer,cars were built before most if them born lol.
Hey thanks man. That's good to know.

So the 85 VK is efi? If that's the case then wouldn't the efi 304 be the best option??

Sorry for the novice questions.... this is my first car build. Ask me about Harleys and I actually know something haha.

Cheers
 
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vc commodore

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Thanks for the advice. The list of things that need sorting out don't seem too bad. I'd rather not mess around with electrics and carb/ manifold conversion required with the injected 304 unless it really is the better option....

Does anyone know if there are any regulations stopping you replacing your original motor with an older year motor? Say dropping a 83 VH 253/308 motor into a 1985 model VK?

Thanks

To convert a 304 from fuel injection to carb, it's a case of removing the injection manifold and bolting on a carby manifold.....Really simple and I'm sure there would be something on u-tube about removing and replacing a manifold. Injected 304's are a little more common that 308's, so price might be cheaper, to help your budget. So it's something to stick in the memory bank.

Early VK's had carbed 6's....Not sure when the cross over period was, but they are out there. I do have a Max Ellery Service manual here, so I can check in that to see when the cross over period came about, if required.

Fitting a 304 or 308 WILL require a disc braked rear end.....Not a drum braked rear end. Commodores fitted with a 308 had them from the factory, so to keep the car roadworthy,(and an insurance requirement if this option is taken) it is a necessary requirement....This started with the VB Commodores and continued right through to the VL's....It was when the VN came on line, was disc braked rears standard across the board and the drum braked rears became obsolite

Fitting an earlier VH V8 motor in shouldn't be much of an issue, providing the pullision gear from the VK is the same as the VH and operational.....But that's something I'm unfamiliar with, so you'll have to check into that.
 

SL/ENUT

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VKs are either carby or optioned with EFi from it series. Only standard EFi 202 are VK Calais
To bolt a carby manifold onto EFI 304, you need a EFI style carby manifold. Normal carby ones of early red, blue or black 308(or VK VL 304's) won't fit, different style in the inlet ports
 

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The efi 304 is the way to go and very easy to do if all you want is a reliable v8 as a cruiser. BUT since it'll need to adhere to adr27a you'll need and engineers certificate if you want it to be 100% legal/insurable.

Lots of people get away with it but I've also heard of people being knocked back by VicRoads. It's a difficult predicament.

As for an older engine in the newer car, that shouldn't be an issue as long as it adheres to the same pollution Regs. For example, vn-vs have the same pollution regs. I actually have a vn block in my vs and all is good with VicRoads.
 

Marco308

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To convert a 304 from fuel injection to carb, it's a case of removing the injection manifold and bolting on a carby manifold.....Really simple and I'm sure there would be something on u-tube about removing and replacing a manifold. Injected 304's are a little more common that 308's, so price might be cheaper, to help your budget. So it's something to stick in the memory bank.

Fitting an earlier VH V8 motor in shouldn't be much of an issue, providing the pullision gear from the VK is the same as the VH and operational.....But that's something I'm unfamiliar with, so you'll have to check into that.

Thanks vc.... that's awesome info.
Finding a VH 308 that actually has the pollution gear may prove very tricky! Unless you can still buy replacement pollution gear?

VKs are either carby or optioned with EFi from it series. Only standard EFi 202 are VK Calais.

Ok thanks man. So an 85 VK SL 6cyl should be carbed?

The efi 304 is the way to go and very easy to do if all you want is a reliable v8 as a cruiser. BUT since it'll need to adhere to adr27a you'll need and engineers certificate if you want it to be 100% legal/insurable.

As for an older engine in the newer car, that shouldn't be an issue as long as it adheres to the same pollution Regs. For example, vn-vs have the same pollution regs. I actually have a vn block in my vs and all is good with VicRoads.

Thanks EYY. Engineers certificate noted.
Not sure that an early VC VH 308 would adhere to the same pollution regulations that the newer VKs would have??

Cheers for all the helpful information guys.... saves a guy like me from making rookie errors.
 

gtrboyy

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Reasonably sure there are 84 model efi cars..it was an optional extra most were carby 202 est crap.

My vk was an early efi 202,pop up buttons with early diff...last ones got slider buttons & 3.23 borgwarner.
Most were calais but few berlina's got them & some povo sl/executive's like mine.

I like efi 304 'cos after effort of doing v8 conversion

Carby v8 has more pollution crap to find/fix/replace then afer all that effort they're heaps slower than efi 304...add extra return line,efi tank & only added pollution gear is catalytic convertor + hook up charcoal cannister that commodores already have.

Dont ask me about Harleys man I cant even ride one haha.
 
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