Deciding on an engine?

[Spartan040]

I am intending to build myself a 1970 Dodge Challenger in a pro touring or resto mod style, and the one I am looking at has an old 440 that appears to be in good, if not serviceable, condition. I am trying to decide if I want to stay with that engine, clean it up, blueprint, flow and balance it, convert it to EFI, and upgrade it to where it's putting out somewhere between 500-600 horses (on premium gas). Or, my other option that I was thinking of, either buy a new Gen III Hemi crate motor or pull one from a wrecked modern Challenger. I am most strongly looking at the 392 (6.4) or the 426 (7.0) stroker motors. I am weighing the pros and cons of both of these options. Thoughts and suggestions?

Oh, and a question about the Gen 3 Hemi, is it really a real Hemi? With the hemispherical head shape? I don't know much about them.

And this may seem like a crazy idea, but is it at all possible to bore out one of the modern Hemi engines (they're all based off of the 6.1 L) to be a true 426, and not just a stroked 426?

[cudabob496]

You can stroke the 440 to around 500 cu in.

[Chryco Psycho]

Either engine will meet your needs so it Depends what you want .
 The Modern Hemis are awesome , true done roof with spark plugs in the center of the chamber , computer controlled EFI drivable & powerful , there is not enough cylinder wall to bore it to 426 these are basically small blocks .
 The 440 can be built to 512 or bigger & will make a ton of power & can have EFI added to them making them very drivable , the 440/512 will make effortless power for a long time .

[Strawdawg]

The current generation head is not a true hemi as it has some squish built into each chamber but the valves are arranged like a true hemi.  In my opinion, it is a better design for a driver and flows very well.

The engines are light weight and capable of quite a bit of power.  I have a friend with a 426 in his Challenger.  I believe it came from Arrington.

If you are going to use the modern transmission with it, it takes some hacking on the tunnel.

As Chryco said, a modern efi on a stroked out 440 makes a great engine with modern drivability and bolts right in.  Add a GearVendors OD behind the 727 and it will last a long time.  If you want manual, there are some od trannies out there that will work well altho the price is not cheap.

[Spartan040]

Okay, so if I went the 440 route, I'd be blueprinting, flowing and balancing the engine after doing a hot tank dip and a magniflux. Then, I'd be installing Pro Comp high performance aluminum heads, Speed Pro forged pistons, a Howard's Cams Hydraulic Flat Tappet HP Cam, Mopar forged 440 crankshaft and rods, windage tray, TTI or Hooker headers, an Edelbrock Performer RPM Aluminum intake manifold, an Edelbrock Pro Flo 2 EFI conversion kit, and either a Flowmaster or Magnaflow exhaust system. My transmission of choice would be a Tremec 6 speed, or possibly a 545RFE 5 speed automatic, or the new 8 speed TorqueFlite 8J70P (if it will bolt up to the old engine). I intend to use an AlterKition front end, further reducing the weight. What would be my likely horsepower and torque output, and fuel efficiency, depending on the transmission?

If I go the 426 stroker route, I'm not sure what upgrades to go for, if any. Suggestions on that? And my guess is the fuel efficiency would be around 12-15 city, 19-23 highway? Also, are the both motors compatible with the transmissions I named?

[Spartan040]

Okay, I've made my decision. I'm going with the modern Hemi engine. My question is, do I go for the 6.4 or the 7.0? It seems like there are many more parts available for the 6.4, unless parts for the 6.4 and 7.0 are largely interchangeable. Is this the case? If I later decide to buy a supercharger, if it's made for the 6.4 will it fit on the 7.0?

[73EStroker]

 Take a bit of advice from a guy who spent $13,500 on a B block engine  and if I had my time over again I would certainly, without hEsitation, buy a third generation 6.4 L hemi for about the same money.  You get all the modern conveniences such as fuel injection parts availability from the local Chrysler dealer and good drive abilities with excellent fuel economy all in one package. I still have carburetor, not great fuel economy etc.

[brads70]

I'm loving my 451" .... revs like a chain saw and all the power the car/chassis/tires can use, and a little more space compared to a 440.  I have around 8k into mine.