Questions about V8 conversion

[Gunns VC]

Hi guys, I am looking at starting a VH project but i have a few questions before i start. I want it to be a V8 and i was wondering if i should go with a 308 or a 304 from a VR or something but i want the 304 to be carbied. How much more work would be involved in putting a carbied 304 in over a 308. I assume a 308 would be fairly easy seeing as they came out with 308's but i also thought a 304 shouldn't be much harder if its carbied?

Let me know what you think, i done a search but found nothin on this subject!

Cheers!

[Darren_L]

the EFI 304 short motor is essentially the same as a carbed 308.
However there are some important differences to consider. Apart from the obvious parts that need to be swapped like intake manifold, the cylinder heads on the EFI engine have a completely different exhaust port layout, which also means they have a different camshaft. Early model heads will fit the 304 block, but you will need to change the camshaft.

the other option is to retain the later model heads and buy a carb intake manifold that fits the EFI heads. There are quite a few available these days. The EFI heads have superior hp potential compared to the carbed heads, so it's a worthwhile consideration. Keep in mind you would also need to buy extractors that are designed to fit EFI heads in an early model Commodore. The most popular choice is Pacemaker, but there are others.

You will also need to find a distributor off a VC-VL as the EFI distributor has no ignition advance mechanism, and no integrated ignition module.
Also worth noting that when it comes to engine transplants from later model cars, in most states you must meet the emission standards of the donor car (identified by the engine number), that means catalytic convertor as well.... goes without saying there is no way a carbed engine will meet an EFI engines emissions standards. So something for you to consider.

[ari666]

go later model heads. do what i didnt do. trust me. spending the cash now on extractors for efi heads will be well worth it. alloy head flow better from stock than cast will flow modded.

[vkberlina]

the EFI 304 short motor is essentially the same as a carbed 308.
However there are some important differences to consider. Apart from the obvious parts that need to be swapped like intake manifold, the cylinder heads on the EFI engine have a completely different exhaust port layout, which also means they have a different camshaft. Early model heads will fit the 304 block, but you will need to change the camshaft.

the other option is to retain the later model heads and buy a carb intake manifold that fits the EFI heads. There are quite a few available these days. The EFI heads have superior hp potential compared to the carbed heads, so it's a worthwhile consideration. Keep in mind you would also need to buy extractors that are designed to fit EFI heads in an early model Commodore. The most popular choice is Pacemaker, but there are others.

You will also need to find a distributor off a VC-VL as the EFI distributor has no ignition advance mechanism, and no integrated ignition module.
Also worth noting that when it comes to engine transplants from later model cars, in most states you must meet the emission standards of the donor car (identified by the engine number), that means catalytic convertor as well.... goes without saying there is no way a carbed engine will meet an EFI engines emissions standards. So something for you to consider.

Also something to add
I have been wanting the old school look while keeping the new model performance. What I am looking at doing is taking off my EFI manifold buying a carbie manifold with injector bosses in it running the EFI and using a carbie as a throttle body basically. Will need to work out throttle position switch, aircon bypass solenoid etc but it should be pretty straight forward as well.

cheers
Scott

[Gunns VC]

Ok thanks guys, yeah like you said vkberlina i want to keep the old school look by going carbied on a 304. How much more work would be involved in putting a 304 EFI over just a 308?

Cheers!

[vkberlina]

not much, running return fuel line, setting up the electric fuel pump, wiring maybe an extra 2 days work in it.

It takes me a day to wireup an EFI 5L into a VB-VK starting with an original VN-VS harness, I could probably do it a bit quicker but everything gets soldered and ta-ped up into looms.

scott

[Gunns VC]

Ok thats not much really. How much do you reckon it would cost to get that stuff done? I don't know much about the wiring side

[vkberlina]

you can buy pre wired kits to make your life easier

where abouts are you located?

[Gunns VC]

How much are those kits? I'm in Victoria near ballarat

[Staggie]

Dunno if you've looked into it Scott but there are 4 barrel throttle bodies with a tps in the out there. Is something I'm currently looking into.

[vkberlina]

Dunno if you've looked into it Scott but there are 4 barrel throttle bodies with a tps in the out there. Is something I'm currently looking into.

I havent looked into it at all yet, even thought about welding up an adapter plate and bolting 1 V8 or maybe 2 V6 thottle bodies onto it, I have even thought about using an old quadrajet gutted out. Heaps of ideas floating around in my head. Problem is thats where they will probably stay I havent had time to touch my car for about 6 months.

cheers
Scott

[ari666]

bah! just go for a quaddy! hei dizzy and quadrajet, stuff your stupid efi if OP knows little about wiring then its the easiest way.