Hey guys im new to this forum and I own a 1971 dodge dart swinger with a 225 sl6. I was going to swap it out for a v8 I have but I decided Id rather be diffrent. I was just wondering if its really possible to get 350 horsepower streetable out of this motor? I seen Clifford has a head for it but do you know any other places to get a head for this motor. I hear Clifford isnt all that great. Thanks guys

If you want 350 hp you'll need forced induction, lots of patience and deep pockets. If you have good fabricating skills you can reduce the costs, but it's still not cheap.

Search the message board and you will find the name of a good head builder. I could just tell you Mike so and so, but what fun would that be?

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Joshua

ok thanks

Welcome.
Start reading and ask detailed questions.

As for 350 'streetable' HP... that is hard but it has a lot to do whith what you think 'streetable' is.

To get 250 HP in a SL6 car you drive everyday, that is not a problem.
Spray it... and you can get your 350 HP but you may burn-up the engine if the set-up is off.
DD

Well I only take it out to crusie the streets at night sometimes. But if im driving for awhile I wouldnt want it to overheat. I cant decide if I should build it up all motor or slap a turbo or supercharger on it.

That's it in a nutshell right there. Nitrous is the only really "bolt-on" boost. There are no affordable turbo or supercharger kits for a Slant. Any forced induction will kill your motor if the set-up is off.

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Official Cookie and Mater Tormentor.

ok thanks again guys

Doug,

What does a buid sheet look like for 250 HP?
Can you post one?
I wouldn't mind building a second engine since my torque and mileage build turned out so well.

Thanks,

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

More head work, more cam and more compression is the basic formula.
Finding the correct "balance" is the trick with pump gas being the main limitation.
DD

Doug,

Understood however,

Do you have to go to headers? or can the stock mainfold "split" with one of your Dutra manifolds for the front work for a 250 hp build?

Is this based on a two barrel super six type set up, or on a 4 barrel Hyper-Pack set up?

Thanks,

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Hi,
Great topic! Doc I understand the formula. Can the stock exhaust manifold support that kind of power? what kind of power can the stock exhaust manifold make on a normally aspirated Slant? and I do not want to use nitrous. Thanks, Nico

A "Super Six" 2 bbl and a factory 6 into 1 cast iron manifold is not going to get you past 200 HP.

To make 250 HP out of 225 CID you are going to need some RPM.
To get the engine to rev to 5500 - 6000 RPM, you will need good airflow.
To get 6000 RPM out of a 225 you will need at least 391 cfm (4 bbl carb) head flow and a cam to get you there.
Some form of 3 & 3 split exhaust gives twice as much time between pulses, this really helps flow.... exhaust scavanging helps even more.
DD

As I figure it, my 62 Toad weighs it at somewhere around 2500 lb. 200hp should be more than adequate for a street cruiser and probably about as much as the chassis can take without some reinforcement. Subframe connectors and/or torque boxes might in the future but higher horsepower probably isn't.

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David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

torque boxes are for rustangs y'know what I'm sayin'

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Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

Yeah, I know wat you're saying but... there were more than a few B and E body cars that were given torque boxes to stiffen the chassis. No reason an A-body couldn't benefit as well.

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David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.