I recently bought a 1968 Mustang that has a Weiand Intake Manifold 8011 and a Holley 4 barrell carburetor 80457s already installed on the 289 motor. I was wondering if anyone knows where I can look to see what kind of horsepower gains (if any) I get with these two components? I am really a novice mechanic so I am trying to learn as much as I can. Thanks for the help.

 

I have a 68 w/ a 289 also. In the near future I would like to add a aftermarket intake manifold & 4 barrel carb. I'm sure it would improve the H.P., but how much is a good question.

 

I did a desktop dyno on the puter, and with a dual plane manifold, and a 500cfm 4bbl carb, it should be really close to around 260-275 at the flywheel...assuming you have stock exhaust, and whatnot. Add a mild cam, and it puts you in the 300hp club. You were probably at 225hp stock, so in the words of Micheal Waltrip...you do the math. subtract around 20% for rwhp.

 

Thanks for the help. The carburetor I have is 600 cfm and I was really suprised that there would be that much gain. I also have a set of Hooker Competition headers installed so I should be looking at around 250 hp at the rear wheels? I appreciate the help.

 

your 68 should have a 302

 

What is the rearend ratio ?

 

I thought they only switched to the 302 in mid year of 68?

Either I am totally wrong on that and it was done in mid 67' instead or you have seen info I have not like a consecutive vin number proving it is a late year model or you have more homework to do before you critisize, either way somethings wrong. Let's all just be hopefull he does not make an Eleahor out of it.

 

No my 68 has a 289. Mustangs were still getting 289's in 68

 

Gearing does not effect horsepower

 

No my 68 has a 289. Mustangs were still getting 289's in 68
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When did the Mustang first get the 302 then?

 

When did the Mustang first get the 302 then?
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The 302 was first available in 68 I believe, but you could still get a 289 until late in the production year. My Mustang is one of the one's with the 289.

 

It is exactly as I said it was which I was sure of but I tried to give you the benefit of the doubt anyway, my bad, I should have just said Livewire was wrong and left it at that.

 

Why are you suprised at the hourse power gain? It's a V8 not a 4 cylinder!

I added those same componets to my 302 and it added around 30-40HP but, I also have 40 series Delta Flow Masters on her.

 

Like I said earlier I am really a novice mechanic. I am very pleased though that you can get that kind of horsepower gains from a few basic parts. By the way thanks for the answer on the Fog lamp question too.

 

It is exactly as I said it was which I was sure of but I tried to give you the benefit of the doubt anyway, my bad, I should have just said Livewire was wrong and left it at that.
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Sorry my brain is currently focused on finals this week :bang:

 

That is the best reason ever, good luck on them. Don't burn out your cells though, once your done you can dump all that useless knowledge and fill the brain with important Mustang facts again.