Advice for Noob with Slant 6 Barracuda

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Dratsum

Dratsum

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Hi Guys / Gals,

My Girlfriend and I just took her 69 Barracuda Mod Top outta storage. She's had it since college (the 90's) and I'm helping her get it restored / running a bit better. She's got a 255 Slant 6, all stock parts and she feels pretty low on power... not a lot of pick up. A mechanic friend of mine said that the carb wasn't in good shape and he suggested replacing it.

If we were looking at upgrades to get a bit more power out of the car, what would you guys suggest? If we go to a 2 / 4 barrel carb, do we need to replace the intake manifold? What about exhaust?

I maybe over simplifying it, but I guess I'm looking a list of suggested power mods / good things to swap, maybe by priority.

Thanks in Advance!
Drats

IMG_5015.JPG
 
Do you guys care about gas mileage or do you just want it to go faster?

You can build slant sixes for decent power but it costs $$$.

If all you care about is power then you need a V8 in there.

If you want some more power while keeping your mileage, 2bbl super six is the way to go.

Either way a slant 6 is a slant 6 and you aren't going to make it as fast as the slowest new car without putting some work into it.
 
Want to keep the slant 6. Not looking for a ton of power, don't want to race her or anything... Just want it to be quicker when we need it. If we got it up to the 200hp range that would be great.
 
Your slant is probably putting out about 115hp when dialed in right. If you want 200hp it's going to take a lot more than just throwing on a 4bbl with headers.

Check out slantsix.org. There's a ton of good information on the forum of slant builds done by various members.

I did the 2bbl super six conversion with exhaust and HEI ignition on my car. I'm not pushing 200 horses but it's not a slug when getting on the freeway anymore either. Those 3 things are the easiest and cheapest mods you can make to bump up the power without tearing into the engine.

I know what you're feeling though, when I had my ill running 1bbl carb I just felt like I was in everyones way because it took the car so long to get up to speed.
 
Thanks ESP47. That sounds like a good place to start. I know that there was a 'Hyper Pack' for the slant 6 that put out like 195 or something like that.. figured 200 seemed like a good goal. I would be surprised if she were putting out 115 hp right now tho.
 
Dratsum said:
What about a Offenhauser 5270LK Single Quad Intake Manifold?

http://www.summitracing.com/parts/OFY-5270LK/?rtype=10
Click to expand...

Throwing a 4 barrel on it will likely make it run worse. It needs to be done as a package. First mod I would sugest is a good electronic ignition. Bolt ons wond do much good on a stock motor. A good valve job and head shave and a more modern cam profile is what it takes to wake these up.If you dont want to do engine work a 2 bbl ,electronic ignoiton and exhaust would be best bang for the buck.Check out Memikes threads on his little 170. Clean little build.
 
Thanks daredevil - I've looked for Memike's post and can't find - could you post a link?

Drats
 
Dratsum said:
Hi Guys / Gals,

My Girlfriend and I just took her 69 Barracuda Mod Top outta storage. She's had it since college (the 90's) and I'm helping her get it restored / running a bit better. She's got a 255 Slant 6, all stock parts and she feels pretty low on power... not a lot of pick up. A mechanic friend of mine said that the carb wasn't in good shape and he suggested replacing it.

If we were looking at upgrades to get a bit more power out of the car, what would you guys suggest? If we go to a 2 / 4 barrel carb, do we need to replace the intake manifold? What about exhaust?

I maybe over simplifying it, but I guess I'm looking a list of suggested power mods / good things to swap, maybe by priority.

Thanks in Advance!
Drats
Click to expand...


rebuild the carb, tune the car up, make sure its safe and just drive the thing.
 
If you are looking for bolt on upgrades, the super six option would be your best option. Outside of that, the heads need to be port and polished to get the best flow to take advantage of the 4 barrel upgrade, as well as better exhaust. I do recommend converting to electronic ignition as well.
 
Just don't swap the intake, do cam, headers/exhaust all at once and do a little head work milling and porting if you want to go that far might not get you 200hp but should make more enjoyable to drive and gear swap would also help.
 
To keep this a none opening of the engine the first thing to do is remove the little down pipe at your exhaust manifold and go 2 1/4' to a new muffler and exit with a 2' over your rear end and out the back, Remove the points and updare to electronic ignition.
Run these plugs (remove the washeres if you still have the drool tube head) I have in the first picture.
doing this will help more then most V8 folks know.. I did a offey 4 barrel but that would be up to you, a good 2 barrel will do well.
 

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daredevil said:
Throwing a 4 barrel on it will likely make it run worse. It needs to be done as a package. First mod I would sugest is a good electronic ignition. Bolt ons wond do much good on a stock motor. A good valve job and head shave and a more modern cam profile is what it takes to wake these up.If you dont want to do engine work a 2 bbl ,electronic ignoiton and exhaust would be best bang for the buck.Check out Memikes threads on his little 170. Clean little build.
Click to expand...

Thank you Brother, hearing you say that means allot :)

Here is the thread Dratsum, some good reading with way to many pictures :D

memikes 66 /6 getting updated Dratsum http://www.forabodiesonly.com/mopar/showthread.php?t=41794
 
Let me jump in here and welcome you if I missed you in the welcome wagon thread :cheers:
I sure do like your daughters/your Barracuda :)
I am sure any info and help can be had here when you need it :cheers:
 
Thanks MeMike - just spent the last 1/2 hour reading yr Victoria thread.. great job man! Wish we had the room to do that kinda work! Living in Brooklyn doesn't make it easy, but I have a friend with a shop who will let me come in and work with him.

Petula is my Girlfriend's car - but - I've been dying to get her running again and get my nails dirty. I'm stoked.

Drats
 
OH - MeMike - I was looking for a complete ignition conversion kit - what kind did you get?
 
It's all mopar, let me see, the easiest way is petronices (how ever you spell it) give me a few min, and I will post it up here, or you can go to ebay motors and type in slant 6 electronic ignition, The kit you see here I bought 3 to 4 years ago on ebayy., but there is a system you can put in your distributor :) all you have to do is remove the points and put it in :cheers:
many folks here have used them :) Petronics... system is a plug and play deal. let me find one or you can see on on ebay for these /6 engines
 

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First, do you really know what high horsepower means? With any engine, max power occurs at high rpm with the engine screaming. To drive like that on the street, you hold it in 1 or 2, or else floor it to keep transmission in low gear. People that drive like that look like dumb kids.

Most people consider high torque at low speed to be "power", like in leaving a stop sign. Think of a H-D blubbing along in high gear and the guy can just twist the throttle to torque his way up. The slant is known for being a torque beast, which is why they were used in full-size pickup trucks and vans. That may be what you really want. For that, a big carb, big valves, and big exhaust won't help much.

First upgrade I would consider is electronic ignition. If your existing distributor is tight (minimal play), you could put a Pertronix ignition in it. I suggest Ignitor II since you can lose the ballast resistor and run a better coil. If you get a later electronic distributor, you can wire an HEI from a GM V-8 easy and cheap, but it won't have the stock look. A used e-distributor is ~$25.

What 1 bbl carburetor does it have? If a Holley 1920, those drove me crazy for decades, giving a rough idle and stalling, until I finally got a good one (4th).
 
Me mike,thinking Pertronix.Swaps,in place,of points,self contained.I prefer ,the method Memike went.You can find replacement stock modules anywhere.Pertronix,one to two days away.
 
Abodybomber said:
You can find replacement stock modules anywhere.Pertronix,one to two days away.
Click to expand...

That is another selling point on the HEI swap. Replacement HEI modules are available in stock in every parts store in america. There is no guarantee that you can find a chrysler electronic ignition box in stock when you need it. GM used HEI modules in just about every truck until around year 2000. Chrysler got away from their electronic box in the early 80's for electronic spark control computers (lean burns). In recent years there have been many reported failures of part store source chrysler electronic iginition modules. HEI modules are still available through GM with the reliability of factory parts.

I had chrysler electronic ignition on my valiant for about a year and the only time the car has ever let me down was when the parts store module fried out in my driveway. I put the points distrubutor back in and never bothered with chrysler electronic ignition again.

Read this http://www.slantsix.org/forum/viewtopic.php?t=15779
 
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