...hmmpf...

So you have both the 302C and the SBF 302 (5.0L) down there and the 5.0L is injected like ours?

 

Lol i also have a set of the 302 aussie heads sitting on the shelf in my garage that all you guys love if that annoys you a little more

 

Hi Aussie1978f100,
The 302C rods are actually longer than the 351C rods (6.025" vs. 5.778"). Some engine builders like them as the reduced compression height pistons tend to be lighter than normal, the longer rod reduces rod angle and increases piston dwell. Other engine builders think the reduced compression height compromises the ring pack and is not suitable for high power engines. I suspect as usual there is some truth to both, and I'm wary of any statement that one engine design decision is always better than another, these things are always tradeoffs.

The 302C heads can be used with a 351C, but you need to use dished pistons to bring the compression ratio back down if you want to use pump fuel. There are a couple of piston makers who make reduced compression height dished pistons for people who stick a 351C crank into a 302C and keep the heads and rods. Of course cutting more material out of a thin topped piston to dish it will make it even lighter, but also weaker... tradeoffs again.

I don't know about Aussie petrol being worse than anywhere else. 302C heads on a 351C with stock pistons will detonate on pump fuel everywhere...

Depended on cam selection, the longer rods can give a higher dynamic compression, but any increase in static compression will be coming from the pistons. Do they have a slight dome or raised section to them?

Anyway, enough of a side trip into engine building... we were talking about EFI!

I believe the Edelbrock RPM air gap is a square bore manifold, so it should work just fine with any of the 4-bbl EFI systems. The runners will be shorter than the Trickflow moving the torque peak up the RPM range slightly, but they look to fairly well matched in length and the air-gap design is a good one.
One of the 4-bbl EFI manufacturers recommended a single plane intake, I can see their reasoning, but I doubt most street driven engines would notice the difference unless the two planes were drastically different.
Some of the 4-bbl EFI have a vacuum test port on each venturi and others test just one or test a manifold fed from all. If the halves of a dual-plane were different enough you'd get one side flowing more air than the other. If the EFI has one test port then it injects the same amount of fuel into each throttle body even if the flow though them is different, leading to bad fuel ratios and bad performance.
Carbs don't have this problem as their fuel delivery is proportional to air flow through the venturi, and if one venturi gets less airflow, then it also gets less fuel, so things stay mostly tuned.
These 4-bbl intakes are mostly designed for carbs, so some of the older designs were less concerned about exactly matching runner lengths and diameters and even flow numbers. The better intake designs, even the older ones, should be fine though.

One day I'd like to do an EFI Offenhauser Dual-port, that would require a lot of custom work, but would be a lot of fun. Probably never happen though, dual-port Cleveland intakes were never made in huge quantities, and I think the wide torque band would be better suited to a car than a truck.

Okay, I'll stop there, I have a tendency to brain dump.

 

No brain dump away matey. You are a wealth of knowledge! I had a friend years ago who rebuilt f100s from the states. He reckoned the fuel there had a better octane rating. Just his opinion i guess. Lol i dont think i will be taking the engine to the engine builder who told me the 302 rods were shorter. I should of done better research. Thank you for correcting me. Regarding the dome shaped pistons..... Is there a brand you would recommend? At the end of the day the truck is going to be a daily driver. Not driven hard at all really. My main reason for going efi is better fuel efficiency and ease of starting. Currently the engine has an msd pro billit distributor, edelbrock rpm airgap manifold, summit 600 cfm street and strip carb with elec choke, double row timing chain and a crow cam. In the shed i have yella terra roller rockers with the hypatec pistons and 302 rods along with the zf 5 speed box. I am thinking about the pavtek 2v cast iron heads. Maybe i am going too far overboard and spending unnecessary money. I would really like to go with the trickflow manifold though. I know it will be alot more mucking about but i think it will be worth it especially since i can pull alot of gear needed off an au v8. I would appreciate Your opinion though on the best route to take if you are happy to do so. I do already have some 302 2v closed chamber heads. Would it be better to clean them up and buy dome shaped pistons or go the pavtek heads? I think i will be pumping out too much horse power for what i really want though. Lol i am always a fan of overkill i really do like torque though. I will add a pic of the cam specs as they mean nothing to me really. Thanks for all your advice. I appreciate it greatly

 

would the EFI Offenhauser Dual-port be going on your ftruck or do you have another toy?

 

There can be a lot of confusion with comparing our fuel and US fuel, they are different, but those differences can be hard to establish. For starters we rate them using different standards, the fuels are tested under different conditions so a fuel that tests well one way might test badly another. They are both sold using octane numbers but they are not the same number and you can't convert from one to the other, though some try. Regular US is 87 AKI, regular Aus is 91 RON, super US is 93 AKI, super Aus is 98 RON. The most common confusion is 91 octane is available both places, but a fuel that test out as 91 AKI is super, and 91 RON is plain old regular.


I don't have enough experience with different brands to be able to recommend a particular one. Most engine builders will have a preference, but it's usually less about one being better and more being familiar with the range so they know the tradeoffs with one pattern over another. There's enough tradeoffs within a single manufacturers range to get your head around without jumping between brands too.

A good builder will know which pistons within a brands range were designed for each given application, some alloys are softer to handle detonation better in an engine on the ragged edge, but will wear out quicker in a daily driver, some will do better with methanol, some are lightened for high rpm, there really are so many variables.

I've looked at some parts listings where there are four seemingly identical parts. All the listed specs are the same, but they obviously have different intended usages, just outside what they can easily put down in a parts book. That's the part you pay a good builder for.

The flip side of that is so much of this variation is for the oddball engines and use cases, and 95% of us are best to stick close to what the engineers at Ford came up with, just with some modern metallurgy tossed in.

You're not going to see a huge improvement in fuel efficiency from the EFI over a properly setup vacuum secondary carb, especially if it's a spreadbore. They really aren't that bad. EFI will really help with the starting, and dealing with any changes in temperature or altitude. I think it's worth it just for that.

Sounds like a good setup.
The 302C heads are great mostly because they are cheap (in Australia) and factory (for the racers who have to use factory heads). They are decent out of the box but they have a reputation for not being easy to tune for more flow, and most critically, time and technology has moved on. There are a lot of more modern designs out there now and they can ignore some of the constraints that Ford had in designing engines that were then used in multiple different cars and trucks.

My truck has a 302C and I'm planning for it to stay that way. The plan is to tune for low engine speeds where the flow limits of the 302C heads aren't as much of a problem, so I'll be keeping the stock heads unless I do something stupid and break something...

The Pavteks will be better than the 302C heads easily. More so if you build for power over torque, but they should be better for torque too.

The cam looks like a nice upgrade while staying mild. Good for torque, not a monster, but monsters are not always nice to live with! It's about what I would put in mine.

There is nothing wrong with overkill!

I like the look of the Trickflow, the biggest issue I have with it is the price, but that's more about my limited truck budget than any reflection on it's value.

Yeah, my only ford these days is the truck, a 1976 LWB F-100 w/302C and a T-18 manual. I had a couple of Falcons but now it's a euro oil burner to commute and the truck for fun.

Cheers,
-F100Rabbit