Hi,
I have a 79 f100 2wd with a 300I6.and want to get a littel more power from my
300. Is ther any thing I can do to the engine to get a littel more power out of my truck .well one thing is when running in third gear it just seems like it gets slower.and sounds like a lawnmower going down the road.is that from my exhaust ?or do you think I have a leak in my exhaust that's making it sound so bad..looking under the truck it looks like a short exhaust .it runs to just Wher the bed of the truck starts and stops and it has a littel pipe that runs from the
Exhaust box.it does not look like most I see on trucks .i like the look with duel pipes that runs out the end of the truck.but having a inline 6 I think that would not work on a inline 6. Am I wrong?

 

This is probably one of the more common questions asked on these forums (probably even a question or two on the first page about it), so do some searches and you'll find a plethora of information.
The 300 wakes up very easily with bolt-ons. An Offenhauser or Clifford intake, 2 or 4bbl carburetor, and improvements to the exhaust will do wonders.

Also, be sure everything else is in good working order. Fresh plugs, wires, cap, rotor, etc. Fresh fluids in your trans and differentials. Repack your wheel bearings so they spin freely. Be sure your brakes aren't dragging.
Etc.

Otherwise, it sounds like you have an exhaust leak. There's a donut that sits between the exhaust manifold and the pipe and it'll often rot out. It's about $5 to replace and is most often the culprit of exhaust noises like you're mentioning. After that, it may be something like a blown exhaust manifold gasket, cracked manifold, rusted exhaust pipe, etc. No way to really tell from our end.

Dual exhaust would be easily doable if you went the route of swapping your exhaust manifold for a set of EFI manifolds. These are the exhaust manifolds from the fuel injected era. They're much higher flow and are a great performance improvement as well. There are also two manifolds, which makes dual exhaust a cinch.



Keep in mind that there really isn't much of a performance gain to dual exhaust, and it's more expensive. But yeah, it looks cool.


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Everything he said. and weight! and tire pressure, etc.
Really like that exhaust system. I just ran that into a Jones Exhaust single muffler (dump after that.. catbacks can look cool.. just weigh more ha) and she sounds like a 289 now.

 

But I can keep the single exhaust and do things to make it sound beefy.i like that hot rod sound.i use to have a gmc with a 350 with 4bbl carb that sounded great coming down the road and at stop lights that bum bum bum sound.

 

What is a good match for a intake manofold and what carb would be a good match for the intake .like if I get a Offenhauser intake whats a good carb for that and a Clifford what carb
Is a good match for that intake. Or does one go with both. Holly or elderbroke .

 

What Offenhauser intake do I get ther is one with a square hole and one with 4 littel square holes.and should I go with a 2 beral or 4 bbl carb.

 

Have you done any searches on the site? All of this has been discussed ad nauseam and all of these questions have been asked, discussed, and answered MANY times and there's a lot of really good information out there for you right at your fingertips.

Two barrel vs. four barrel is a personal preference. I like a 4bbl because the smaller primaries can get better gas mileage. But, that goes away once the secondaries open, so that's all dependent on how light footed you are.

Edelbrock vs. Holley is another personal preference. They're both very different from each other in design so it's whichever style you prefer.

The Offenhauser C and the Clifford are both open plenum (the big open square), which can take a 1bbl, 2bbl, or 4bbl. The Offenhauser DP is four barrel ONLY.

A 390 - 500 cfm carb is generally a good choice, but a 600 will still work if that's what you have.


As for exhaust, you'll never get a straight six to sound like a V8. It's in the nature of the design and there's nothing that can change that. That doesn't mean that a 300 can't be made to sound nice and beefy though.

 

Thanks for the info.i will Leo some searching. And the intakes are exspensive.like Around$300.00 for the intake manafold .

 

Abandon bronco when you say you can make a inline 6 sound good what do you mean?
If I find I have a exust leak at the exhaust manofold .is ther somthing I can change while I am taking them off anyway could I install the EFI manafold like in your picture to make it sound better?

 

Fuel Injection!

I used an alternative to Megasquirt, VEMS and now the '78 moves! I had a '75 van with a 300 and it's pitiful compared to EFI.

The idea is that there are no restrictions in the carb (The Carb is a venturi and is a natural restriction) and has precise fuel metering and smooth power. Also, when bouncing in the boonies, there is no carb to be flooded.

Mind you, EFI does complicate things and diagnosis can be problematic if you don't know what ya is doing.

 

I don't think a 300 can sound like a v8.

 

An Inline 6 sounds better than a V8 anyways

 

I should record mine.

 

I don't plan on puting fuel injection in my truck .mybe just the EFI headers.

 

A 240/300 can sound great. But when you rev a 300 it's going to sound like an inline 6 not a V8.

Here's a cammed 300 with open headers.



Here's a 300 with a 268H Comp cam running through an exhaust system. It sounds more like a Detroit Diesel then a V8.



And a couple other vids.





You can change the sound some by changing the manifold/s or header type, the size of the exhaust pipe, single or dual exhaust, the type and size of muffler, the length and exit point of the tail pipe/s. But the inline 6 will always sound slightly buzzy when you really rev it out. The inline 6 has it's own sound due to it's design. I personally like the sound of the big 6. And I think they can sound wicked. But if you really need to have the exhaust note of a V8, well then you are stuck swapping in a V8.