Hi There!! Newbie with questions.

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Avenger2040

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Hi to everyone, I got this question, first I got a ´71 Valiant Duster with a Slant Six engine and I wish to swap it for a V8, my goal is to archive a good mileage with high horse power and torque, but without turbo.

What I got now is a Rochester Quadrajet (don´t know model) and four speed gear box (also don´t know model), I live in Mexico City, so there is no laws for cars so setups that make cars non-street legal don apply here, and enviorental regulations are no problem.

So wich engine is better for me: 318 or 360?
 
Welcome aboard. If you can find a good 360 you start off with an extra 42 cubic inches and lots of low end torque. That's money you can save trying to get the extra HP out of a 318. :)
 
Great!, thanks bud, any advise that I need to know for the swapping prosses?
 
Cubic inches with high gears is the only way to easily accomplish your goal. Consider that my 340/727/3.23 GTS convertible gets the same fuel mileage as my son's 440/4sp/3.23 GT convertible. That is about 10-12mpg in town and near 15mpg on the highway. I suspect the 440 car would benefit greater from a swap to 2.94 or 2.76 gears and still feel strong.
 
Avenger2040 said:
my goal is to archive a good mileage with high horse power and torque, but without turbo.QUOTE]

2 turbos? 360 if ya can 318 if ya must, neither are exactly gas savers.
Click to expand...
 
Ok, so the best engine to get is 360 right?, I will try to take some pictures of my gearbox so all of you can identify it, also, years ago, previous owner change differential for one of 10 bolts, I think that was used in V8 Dusters.
 
No, I don't agree that the 360 is the right engine for the goal. If I were to install 2.76 gears in my 340 GTS convertible it would be an absolute dog and only achieve slightly better mileage. On the other hand, if we installed the same gears in my son's 440 Dart we might get close to 20mpg on the highway and still feel strong. Your goal requires cubic inches AND high gears.

And, building a big block a-body is really not difficult.
 
For a change in engines, it's ethier a correct K-frame swap or a swap kit from http://www.engine-swaps.com/ for less money. Excellent instructions are included.
Your goal of high torque is best and easiest to achieve with a 360. The extra throw of the crank is great in torque production.
I had a '79 Dodge Magnum (Think Cordoba with a different nose and hood if you don't know what it looks like) with a 360/904/2.76 gears getting 20 mpg's.
The only mods were a 2bbl. swap to a Carter 625 on a factory intake, MSD, Dual exhaust of the manifolds and a viscous fan.

Theres only 1 4spd. manual gear box for the Chrysler line up. It is the A-833. Theres one varient, the overdrive version. I.D.ed by a case mounted lever fliped upside down. O.D. versions came in iron and aluminum. Theres 2 front bearing retainer sizes. I think you would want to skip the weaker O.D. unit to handle high HP & torque.

I believe you can achieve your goal of 20+ mpg's.
 
Those aren't the only choices for the big block swap. There's the home-built DC k-member, elephant ears, custom mounts, etc.
 
Okey them, I will get a "67-72 A-Body S6 to Small Block Conversion" kit from Schumacher and the 360 engine is quite easy to adquire, problems are when you want bigger Mopar engines.

So that is the model of my 4-speed gearbox, but rumblefish360, you think that gear box will not be able to handle big HP and Torque?
 
Whats big HP and torque? I've put over 400 lbs of torque to it. Not what I would consider big. But a whole lot more than stock. You could ask this question to Andrews racing trannys. They might know about the limits of it's abilty.
Theres also http://www.passonperformance.com/
J Passon is a good guy that can help with a few questions about the Chrysler 4spd.
Another choice, http://www.keislerauto.com/
Though expensive, I have not heard a bad thing yet. Tremacs are a newwer designed tranny with models able to take some serious power from the engine.

Also, whats good mileage? And what kind of 1/4 mile times would you like this engine to perform in. Not that I think your taking this to the track to race. You could. But thats not what I was thinking you'll be doing with it. Just looking for a idea on the performance you want out of it.

Big inch small block MoPars can be done. Just how big do you want to go?
 
Well I was thinking to get the 360 as close to 400 HP and Torque, an of course it will beat my Slant Six in quarter mille (current track times is 15.680), my gas milleage is something like 15-17.

So I wish to get something like 13.600 to 14.200 in 1/4, and since V8 drinks more gas, 13-15 mileage, if more is possible with the desire track time better.
 
Without a doubt, I thought you were leaning towards big power out of this engine. Something allong the lines of 750 HP plus. You did say big power now didn't you.....sefus & Jim Lusk were thinking along the line of some more power than you just suggested and thought with me on some hi HP levels.

Look, 400 HP is done easy. Build it right. Keep it clean, and then cleaner.

If your going to use stock iron heads, bowl port and clean up the runners with stanless steel 2.02 & 1,60 valves. Keep the ratio no more than 9.5-1.
Use headers with 2-1/2 inch exhaust.
An excellent intake and carb combo is a Edelbrock RPM, air gap or not and a 750 cfm carb. Brand is your choice.
A basic cam to use for this power level is a MoPar purple cam rated @ 280* of duration and .480 lift.

Aluminum heads require a little more ratio. 10.5-1 max. In example, Edelbrock heads (Unported) and a zero deck piston like a KB107. Use with a Fel-Pro gasket @ .039 thick.

That'll get you where you describe you want to be. Gas mileage and 1/4 mile times gear ratio, tire size dependent. Not more than a 3.73 gear needed. 3.55's should be fine.
 
Shoot a high 13 quarter and only looking for 13 - 15 mpg? Give us a $5-10k budget and we are gonna go hog wild! Honestly a 318 can make 400 although a 360 will do it easier and if you are swaping form the slant, I say go for the bigger cubes BUT if you say had a 318 laying around, thats a free block to use. Anyway iron Xspec heads like rumblefish described, depending on what octane pumpgas you want to buy, your compression can go from 9.5 on 87 to 10.5 on 93. High compression is going to require more money and a tighter engine and tune, but one by-product of it is better mileage, the other being higher torque and HP.

Anyway thats enough rambling, Rumblefish has you all set for a good street setup. Personally I cant wait to blow this combo up and fab up the headers for my twin t-66's.
 
Great thanks! I will start buying things to make the swap, truly I was getting very tired of slant.
 
Avenger2040, I f you get a 360 and you want to get any good power out of it, dont expect more than 10mpg in the city and 14 on the highway. Shoot for a late model 360 with swirlport heads (308 casting). Rebuild it right the first time. Take it to the machine shop and get the works. Line honed, bored if needed, cleaned and magnafluxed, Square decked and then buy some forged flat tops and have the shop balance the rotating assembly you will use. Assemble it all and get you a good cam like they said. Rpm air gap and a good vacuum secondary carb (eddy's are easier to toy with) and you should be sitting at around 350hp with 400lbs ft torque easy. That is a perfect setup for 13's. keep your tranny. Your gear ratio's are perfect for racing around. Depending on what rearend you got whether its got a diff cover or not( 8 3/4 has no cover but only unbolts to remove the guts) ck to see if there is a metal tab with some numbers stamped on it attached to your differential. PM me back if you have further questions
 
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