Looking for help with 289

SKessler said:

I am a proud new owner of a 1968 fastback 289. It has the original 2brl carb. I am looking to add some HP. Would replacing the carb with a 4 brl be the right thing to do? If so, what kind do you recommend? Is changing the intake a good option? I am interested in any other ways to gain some power with out doing anything major to the original motor. Any ideas? I am new to these forums as well so any help is greatly appreciated.

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You'll get about 20 hp increase if you install a 500 cfm carb to replace your 2V. Don't go bigger, a bigger carb than that will make it run worse, not better. Replacing the intake manifold is mandatory. The Edelbrock Performer RPM or Cobra are your best choices, but even a stock iron manifold will do, I have that on my 289HP and it seems to run pretty good

You may actually pick up just as much power by having your distributor advance curves adjusted. I have done quite a few of these, NEVER saw one that was in limits. The results can be quite astonishing. If you are upgrading to 4V, this is mandatory anyway.

There are other low-buck things you can do to increase power, such as camshaft replacement and cylinder head exhaust port-matching. The stock exhaust ports on these are so bad that port-matching is more important than switching to dual exhaust.

Hi,

To wake it up a little, on a limited budget, start with:
(keep in mind, these suggestions work as a package ....air/mix in ..... air/mix out >>
Keep it simple, until you decidejust how far you want to take it.
Also, fine tuning what you have already, is always the first recommendation.

1. Eddy 600 CFM model 1406, or Holly (which ever flavor)
(From my experience, the eddy is a lot more user friendly)
2. Eddy dual plane (Performer)
(good basic torque build'g intake)
3. 2.5" dual exhaust w/TRY-Ys (coated) and balance tube
(in the long term, this will cover most of your street warrior power requirements)
4. install a Pertronix sparkie
(just get's rid of the need to diddle with points)

These suggestions will work well together to build a little boost for a street cruiser and daily driver. You are looking to increase torque for a nice street car with attitude.
However, you will have learn ( if not already) how to custom tune any carb you stick on there. It should be no larger than 500-600 CFM range for what I'm suggesting as a start.
For tools, you'll need a timing light and engine vacuum gauge for tuning.
Experiment with initial timing 10-12" range.
Learn how much mechanical advance is in your dizzy.

Happy Motoring!

Congrats on the buy, as like many suggestions above, those are great. I had the same engine, put a holley 600, performer rpm intake, full length headers, 2.5" mandrel exhaust, and an accel points conversion on my car. Of these mods the best one by far was the cheapest, the points conversion. Some people are apprehensive about buying a holley carb, I just wanted to say I bought mine (600 vaccum secondary electric choke) Bolted it on and tuned the idle circuits (took 5 minutes) and it works great, no hesitation, but I can't talk bad about an edelbrock, never owned one and they sell a bunch of them. To sum it up, after all of those bolt ons the car went from barely being able to turn over the tires to a wheel smoker, all of that probably netted me 30 horsepower according to my butt dyno, really improved my throttle response as well. Have fun!

for a budget build, i would put on a weiand action plus intake with an edelbrock 1406 carb. the 1406 is a 600cfm carb with an electric choke. the nice thing about the edlebrock carb is that it has smaller primaries than a holley 600cfm carb, though larger than a qjet.

for the exhaust i would use tri-y headers and dual exhaust.

that should get you a gain for about 40hp or so with no other changes.

Maybe a clarification could be good here.

What are the differences between the suggested intake manifolds?? The Edelbrock performer RPM, Cobra, Weiand action plus where the ones mentioned. I have a Weiand Stealth.

Also someone recommends 500cfm while other recommends the bigger 600cfm. Isn't the 600 too big for a stock engine??

68xstang said:

Maybe a clarification could be good here.

What are the differences between the suggested intake manifolds?? The Edelbrock performer RPM, Cobra, Weiand action plus where the ones mentioned. I have a Weiand Stealth.

Also someone recommends 500cfm while other recommends the bigger 600cfm. Isn't the 600 too big for a stock engine??

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The eddy Performer RPM ( I run this) is a high rise dual plane intake and is really designed for a RPM range of 1500-6500. Since you are closer to stock, this is why I suggested the low rise version or Eddy performer. If you were to throw a little more cam in there, then the Performer RPM , would be a nice fit.
The 600 CFM can be easily tuned, in two directions. Down for your current application and upward when you start adding more power making goodies.
As an example, my 600 & Performer RPM supported me from 302 to 331 and making 348 RWHP. I'm still running the P_RPM under my dual Webers.
Happy Motoring!

68xstang said:

Maybe a clarification could be good here.

What are the differences between the suggested intake manifolds?? The Edelbrock performer RPM, Cobra, Weiand action plus where the ones mentioned. I have a Weiand Stealth.

Also someone recommends 500cfm while other recommends the bigger 600cfm. Isn't the 600 too big for a stock engine??

Click to expand...

The difference is the high rise dual planes(Stealth, RPM, Ford A321, Shelby's old "Cobra") make power from idle to 6500 rpms, while the low rise intakes run out of breath at about 4500=5000. If you're going to do more in the future, go with a high rise dual plane. Otherwise replacing the stock 2 bbl intake with a Performer or Action Plus is pretty much a waste of time and money. You'd do better there by simply replacing the 2 bbl carb with a Holley 500 cfm 2 bbl.. My pick ? Any of the high rise dual planes topped by a Holley 570 Street Avenger.

SKessler said:

I am a proud new owner of a 1968 fastback 289. It has the original 2brl carb. I am looking to add some HP. Would replacing the carb with a 4 brl be the right thing to do? If so, what kind do you recommend? Is changing the intake a good option? I am interested in any other ways to gain some power with out doing anything major to the original motor. Any ideas? I am new to these forums as well so any help is greatly appreciated.

Click to expand...

Right now, Autozone has the Eldelbrock Performer intake manifolds on sale. They were $189, and now are only $99. That's a deal, as the cheapest I could find them anywhere else was $159. I bought one...

Craigslist can be your friend for hard parts that are used, like an intake, or carbs, headers, etc...

Ogre said:

Right now, Autozone has the Eldelbrock Performer intake manifolds on sale. They were $189, and now are only $99. That's a deal, as the cheapest I could find them anywhere else was $159. I bought one...

Click to expand...

This is a great option for you.

Yes a 4v carb will wake up your Mustang. A 500 or 600 cfm will be plenty. It will match most of your future mods as well.

Later you can do exhaust to give it more horses.