I would love great advice. I have a 1971 dodge dart custom 4 door. I want to make it into a sleeper. It currently runs great, looks great, 85,000 original miles on it, all stock except the ignition kit. I want to redo it all. Wheels/tires, paint, custom interior, but mainly the engine. I want to keep the 225 slant six, but need extreme advice from the knowledged. I've heard a different crank, different intake, and a 4 barrel carb can do the trick? PLEASE CORRECT ME IF I'M WRONG. All internal the same or do i need different rods and pistons? It's probably cheaper buying a "SUPER SIX" engine, but i take pride in what i own. I want to build it. Anyone with any experience or knowledge of this would be greatly appriciated, and i'll most likely make your time worth it, just becuase i'm a nice guy like that. THANKS CHARACTERS! HAPPYNEW YEARS.

 

I think your question rests with just how radical you want to make the Dart? My experience has been that a standard 225 reacts very well to updated ignition (which it sounds like you have), four barrell carb set up and header w/ free flowing exhaust. Add a 3:91 axle ratio to it and you've got something that nobody is going to expect from a 60's 4 door!

If you go more radical, with crank, bored and pistons then you'll gain even more obviously - but it is significantly more expensive.

Hope that helps

 

Don't go much bigger than a 625cfm carb, the cylinder walls will not like it! (I know this from experience) P.S. if you can find a Clifford Research manifold that would be the way to go. They seem to be a bertter manifold than the Offy in my opinion

 

The "super Six" is not any more of a performance motor than your, merely a marketing name. It will wake up your existing motr up quite a bit to install a 4-bbl Clifford manifold and headers. The Headers are a dual design which will give you true dual exhuast. A Holley 390cfm carb will do nicely unless your going with a Procharger or Turbo kit. (yes - there is a bolt-on procharger kit for the slant 6).

Check with the guys at ProMax Carbs and Performance in Indy, they are Clifford dealers, can setup the carb, and even get you a ProCharger kit. ProMax has a 225 Duster they race so they do more than just sell you stuff!

Scott