Dodge 383 HP vs. MPG?

[moronmountain]

So I recently bought a 74? Dodge Power Wagon 3/4 ton, long bed, 4x4, club cab with a 360 and manual ******. I've located a 383/bell housing to replace the 360 with. Assuming I have a 4.10 rear end and manual locking hubs, what are the odds I will be able to get 10+ MPG and still be able to achieve 350+ HP? I know this is a strange question here, but I didn't get any answers on a Mopar forum. Also I was hoping to use 3 2bbl carbs rather than a single 4bbl for looks. Am I dreaming, or is this possible?

 

[barney rubble]

10+ mpg? No way. JMO.

 

[moronmountain]

10+ mpg? No way. JMO.

Well I get 9.5-10 in my 95 F350 quad cab with a 460. It just seems like it should be doable in the Dodge with a 383 if I leave it fairly close to stock. Heck I don't know...............

 

[tonydanzah]

i think a soft foot and 4 bl should get better mileage than a 2bl. The primaries are smaller on the 4bl.

 

[Major Ramifications]

You need to get on Ramchargercentral.com. It is the place for trucks like that and questions like this.
I would say, that without an overdrive and those 4.10 gears, 10 MPG will be out of reach. But like I tell the guys on that board, if you are concerned about MPG, you are driving the wrong vehicle.

Congrats on the Power Wagon purchase!

 

[moronmountain]

You need to get on Ramchargercentral.com. It is the place for trucks like that and questions like this.
I would say, that without an overdrive and those 4.10 gears, 10 MPG will be out of reach. But like I tell the guys on that board, if you are concerned about MPG, you are driving the wrong vehicle.

Congrats on the Power Wagon purchase!

I'm not that worried about it as I have other vehicles to drive. I just want to get the best ratio that I can MPG/HP-wise, and still be able to drive the thing around once in awhile. FWIW I'm guessing on the gear ratio as the truck isn't parked at my house right now. I'm just trying to think worst likely scenario.

 

[GeorgiaHybrid]

I agree with 4.10 gears you will be lucky to get 7.5 to 8 mpg with that rig. Don't be surprised if it comes up at 6 to 6.5 mpg if you are shooting for 350+ HP.

Edit: If this is for street use, drop in something along the lines of a 3.20's rearend gear.

 

[speed bump]

Are you talking about on highway or around town?

If it was my rig and that was the goal here is how I would approach it.

Run about 9:1 compression
Go with a modern dual pattern cam with an emphasis on low end torque
Hot ignition, I don't know if mopar stuff is worth a **** or not but it seems like most of my mopar friends run aftermarket stuff
efficient intake and if your a big spender aftermarket heads.
Synthetic low viscosity oil (5w-20 or 30)
If your rebuilding the whole thing, moly rings, tight bearing specs, coatings if you like spending money
If you stay with a carb probably go with a holley 4160 with a dual stage PV in about the 600 cfm range.
Electric fan or clutched fan

Since there is no replacement for displacement I would probably sell the 383 and buy a 400 out of a 1 ton dodge and come out ahead money wise.

Other things to consider
changing gears if you have a good transmission you could drop down to about 3.55s and be still be able to do truck work. Or be lazy and do what I decide to do and run 37s.

Skinny radial tires have lower rolling resistance. Mud terrains look cool but the cost mileage as well so buy the least aggressive tire you can get away with.

As far as the original question, I can get 11-12 mpg on the highway at 60 in my stock 71 Ford with bias plies and 4.10s but you end up driving 55-60 instead of 75 like everyone else so yours should be doable since its a shorter truck with slightly less brick like aerodynamics.

If your lazy throw in a diesel and experience 20mpg.

 

[leftyz]

you didnt say what size tires either

 

[Major Ramifications]

Also, is there something wrong with the 360? They can cheaply be stroked to 408-410 cubic inches, which is bigger than a 383 with tons of torque. Then you wouldn't need all of the big block swap parts, either. If you have your heart set on a big block, 400's are the cheapest, and 440's are the torquiest. 383's only make sense in a restoration, or if you already have one ready to go.

 

[moronmountain]

Also, is there something wrong with the 360? They can cheaply be stroked to 408-410 cubic inches, which is bigger than a 383 with tons of torque. Then you wouldn't need all of the big block swap parts, either. If you have your heart set on a big block, 400's are the cheapest, and 440's are the torquiest. 383's only make sense in a restoration, or if you already have one ready to go.

The 360 has a spun cam bearing. I have a special place in my heart for 383's. I had a 64 Chrysler with one, and my dad had an old ex-police car Plymouth with one. It's kind of sentimental in a wierd sort of way. I know 440's are torquier, but 383's are snappier IMO. At any rate, I have already located a complete 383 with a bell housing. I can find cheap 440's all day long, but the bell housing is the hard piece. I'm not too fond of 400's though I must admit that I have little to no experience with Mopar 400's. If I wasn't going with a 383, then I would just do a 440. I can find them all day long for less than $500. I'm hoping the final ratio is less than 4.10, but I am planning for the worst. I have my F350 to pull with if I need that, but I would still like the Dodge to be able to do it's job if/when it ever became necessary. I plan on running either regular old 235/85 16's or 285/75 16's depending on which looks better to me at that point. I won't lift it any more than 3", so I doubt 35's would fit under there. I also prefer 10 ply tires in case I have to put some weight in the bed.

In answering the question about around town vs. highway. It's been my experience that with low gearing a person normally gets the same mileage in town, on the highway, loaded or unloaded with a gas motor, so I was thinking more of an average. Deisels on the other hand............

 

[moronmountain]

Are you talking about on highway or around town?

If it was my rig and that was the goal here is how I would approach it.

Run about 9:1 compression
Go with a modern dual pattern cam with an emphasis on low end torque
Hot ignition, I don't know if mopar stuff is worth a **** or not but it seems like most of my mopar friends run aftermarket stuff
efficient intake and if your a big spender aftermarket heads.
Synthetic low viscosity oil (5w-20 or 30)
If your rebuilding the whole thing, moly rings, tight bearing specs, coatings if you like spending money
If you stay with a carb probably go with a holley 4160 with a dual stage PV in about the 600 cfm range.
Electric fan or clutched fan

Would you go with steel or aluminum crank, rods, etc? Give me an example of a "hot" ignition. It's been a LONG time since I've researched gear head stuff like this. I know Mallory used to make ignition stuff. I would REALLY like to run a 6 pack for looks. Is there a way to use really small 2 bbl's linked in series so it act's like a triple stage single carb? So basically if I keep my foot out of it, it will only be using the first carb? Any links to aftermarket engine parts would be sweet. Thanks for all the feedback!

 

[gorilla]

I have a 1969 1/2 ton Dodge Power Wagon powered by a 413, 650 holley mild cam, dual exhaust. I get 10 mpg no problem. 3.55 rear end 33" tall tires.

 

[nate379]

Wow and I was complaining that my old diesel one ton only got 15-16mpg

 

[willymakeit]

You can run 3 2's as the manifolds are around, just have to search. They were aftermarket in the 70's. Run vacum on the secondarys instead of mech. linkage. There are other facors, but I did run a 383 11.1 comp.and a .485 lift cam inthe late 70's. 4spd. 3.91 gears and a 26" tire. Best was around 16 at 55mph. Car weighed around 3600 lbs.

 

[Major Ramifications]

I would really appreciate some pictures and more specs on the truck. So, it sounds like it is a 3/4ton? Did you check out Ramchargercentral.com? They would love to see it over there and hear about your plans.

 

[moronmountain]

I would really appreciate some pictures and more specs on the truck. So, it sounds like it is a 3/4ton? Did you check out Ramchargercentral.com? They would love to see it over there and hear about your plans.

No I haven't checked that site yet. I'll take pics as soon as I get rid of my firewood so I can get it home. It's a 3/4 ton, club cab, long bed 4x4. It has a manual ****** and manual locking hubs. I'm buying it from a guy that has had it for 31 years, so he's pretty close to the original owner. I'm not 100% of the year, but based on the grill I think it's a 73-74. The previous owner recently replaced the box, so that's one less thing I'll have to buy. It needs a ton of TLC, paint, etc., but the whole thing is there, and it's not completely rotten. I hope to have it home next weekend, at which point I'll put up pics/specs/etc.

 

[mikevango]

3 2 barrels? why put a $1800 induction on a $500 truck? find another 360. maybe a magnum with a carb.

 

[slopecarver]

I don't know if you could get that sort of mileage out of it but I'm sure I could. You are attacking the problem all wrong, you should adjust the nut behind the wheel first, not the truck. visit cleanmpg.com and ecomodder.com to learn how to improve your driving habits. I believe there are even a few people there who have big trucks (f350 size) who keep a log of their mpg so you could compare. I personally have a 00' s-10 4.3 v6 4x4 with an epa highway of 19, during the summer I can get tank averages of above 24 mpg, thats a 25% increase without changing the vehicle at all.

 

[moronmountain]

I don't know if you could get that sort of mileage out of it but I'm sure I could. You are attacking the problem all wrong, you should adjust the nut behind the wheel first, not the truck. visit cleanmpg.com and ecomodder.com to learn how to improve your driving habits. I believe there are even a few people there who have big trucks (f350 size) who keep a log of their mpg so you could compare. I personally have a 00' s-10 4.3 v6 4x4 with an epa highway of 19, during the summer I can get tank averages of above 24 mpg, thats a 25% increase without changing the vehicle at all.

Um how can you expect to know what my driving habits are?

 

[moronmountain]

3 2 barrels? why put a $1800 induction on a $500 truck? find another 360. maybe a magnum with a carb.

I already have a 360 that is fixable. Why would you care what kind of cars I want to put on my own vehicle? The truck will be worth alot more than $500 when I'm done with it, but that's still not the point. It's mostly going to be a toy that is a classic, and I want to keep it in my family.

 

[slopecarver]

Um how can you expect to know what my driving habits are?

thats why I said "I don't know if you could" Emphasis on the DON'T, KNOW and YOU

 

[mikevango]

Hey slopecarver I see you're in Erie too. Small world.

 

[moronmountain]

thats why I said "I don't know if you could" Emphasis on the DON'T, KNOW and YOU

"You are attacking the problem all wrong, you should adjust the nut behind the wheel first, not the truck." This statement indicates that you know something. IMO it completely undid what you said in your first statement. I have fine reading comprehension. I'm not trying to start a ******* match, but am just asking for helpful imput to my question. Thanks.

 

[slopecarver]

hey sorry bout that, good luck in your mpg endeavors

@mikevango, I've lived here for 4 years, moved up here for college. I don't really have much of a garage but the one I do have ***** more than most.

 

[moronmountain]

hey sorry bout that, good luck in your mpg endeavors

@mikevango, I've lived here for 4 years, moved up here for college. I don't really have much of a garage but the one I do have ***** more than most.

NP. I'm prolly being bitchy from staying up too late last night hehe. Thanks.

 

[trainer]

how about a slant six?