OK, I'm dumb, need help

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Murray

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Been a Mopar nut all my life but have never really paid much attention to /6. Am considering a performance build of a /6. Have looked at the Clifford complete setup and am impressed but I would like to know what more is out there. Is more performance available? Can it be stroked? How about more cam? compression? Is better ignition available w/o a plastic drive gear? How far could a person go? Thanks for the input.
 
Here's some cool setups.

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The best sound a slant six makes is the T H U D sound when you push it off the tailgate into the mud before driving away.
:rofl:
 
Kern Dog sounds like he feels on a slant like i do, i had a 73 dodge pickup, 3 on the tree, if it got below 10 degrees in winter you may have well walked to work, i live at about 3000 ft elevation, and when i get out of the driveway its 1 .5 mile off what we call the ridge, i would roll it off the carport, put it in 2nd gear and be running about 70 mph , pop the clutch and it would blow smoke for 1/2 mile and finally start, didn't use any oil, and compression was good, but turned me away from the 225s for life
 
Been a Mopar nut all my life but have never really paid much attention to /6. Am considering a performance build of a /6. Have looked at the Clifford complete setup and am impressed but I would like to know what more is out there. Is more performance available? Can it be stroked? How about more cam? compression? Is better ignition available w/o a plastic drive gear? How far could a person go? Thanks for the input.

You can go as far as the money will allow. Myself, I am a low budget slant six racer, There are others that have more in there engines, then in a new truck, and any where in between. Do not buy a complete Clifford setup. Much better stuff available elsewhere. The only things I would consider from Clifford, would be intake manifold and/or headers. There are other vendors for these parts, also. My advise is don't jump in with both feet, untill you do some research, and ask questions. Slantsix.org is a good resource for slant six performance.
Here is a video of what is probably the ultimate slant six car.
 
I’ve owned slant 6 aka “/6” and v-8.
No matter how much an AVERAGE guy pushes the /6 they will never be a large horse power motor. This is due to a really limited head intake and exhaust port based on the smaller /6. Yes people have reworked them and run 300hp. After the Clifford trials and errors on mine I decided to V-8 with fuel injection. Smoother, way more power and in my opinion only... better bang for your buck.

With that said the /6 has a huge following and honestly nobody has built a better known or more reliable 6cyl engine than the Chrysler /6. “6 in a row make it go!”
 
With that said the /6 has a huge following and honestly nobody has built a better known or more reliable 6cyl engine than the Chrysler /6. “6 in a row make it go!”

Agreed!
Those engines run forever, dependable and cheap to run ( in there time). In my early years, I had many, wish I had that collection now.
 
The best sound a slant six makes is the T H U D sound when you push it off the tailgate into the mud before driving away.
:rofl:
I agree. Dollar for dollar spent, you get a bigger bang for your buck with a V8. That said i had 3 cars with a slant sux. 66 coronet 440 2 door hardtop, 1970 barracuda, and my current 67 barracuda. The coronet i sold with the engine running around 1987. The barracuda i sold to a guy wanting to do a hemi swap also engine running around 1988. My current 67 the slant sux made a nice thud when i dropped it off at the scrapyard after kicking it off the end of the trailer. I offered it complete here for FREE along with its transmission to anybody who wanted it. No takers for months. i figured that i will get scrap price for it. Big magnet picked it up, and right into the shredder it went.
 
This is what I'm looking for! Appreciate all your comments and sense of humor. I am not chasing a horsepower number. Just want to understand the length and breadth of what can be done to a /6. It may be that a mild build is best as far as reliability goes. What is your opinion on early heads (w/ spark plug tubes) and later heads (w/o plug tubes)? I am drawn to this build because it is different and a hi/po /6 sounds incredible.If a person doesn't go all Clifford, what would you change? Thanks for the input.
 
Theres sites i have seen that talk about how to port one, and which head castings are best for performance, as well as limitations based on runner design because of pushrod location. Every little bit helps.

The problem with the 225 slant stems from the earlier design. Before the 225 was thought up chrysler had the 170 , and 190 slants. It was closer to a square engine. Small bore short throw crank. These were small inch but rev happy for a 6. Being that the bore spacing was already set, machining tooling was aleady on the assembly line, and the need to come up with a bigger engine popped up. Chrysler raised the deck height, and designed a different crank to go in the new block. This resulted in the same small bores with a longer stroke. Not the best in terms of performance.

My recommendation is to find either a 170, or a 190 slant, figure out which head to run. I believe slanty heads can be milled safely to .100", .120" to bring up the compression. In this case you will have to lop off about 1/8" of the bottom of all the head bolts so they dont bottom out before they torque the head down tightly.

I had a 69 dart slanty i did a head gasket job for somebody years ago. Took .100" off the head to get the warp out of it. Ended up cutting 1/8" off the ends of all the head bolts so they wouldent bottom out.

I could be wrong with some of my recommendations, however i am not wrong on the head milling and headbolts.
 
There used a be a guide to angle milling the slant six head over on slant six.org for more compression and adding some quench for burn effiency. THe 198 blocks and 2.25 were the same, the 198 was a de-stroked "econo" version of the 225 with a 3.64 inch stroke and 7.006 rod. I have only seen one that I was aware of, but the stock performance was identical to a 225 in an a-body. Most hardcore slant six racers use the 4-1/8 inch crank with the longer rods with lightweight pistons. If you look up Pishta on his home page, he has some homemade intake setups if you choose to be in the "dare to be different" club. A properly built homemade intake or one of the Chrysler hyper-pak manifolds are the best bet. The best 225 to build IMO is a pre 1976 truck engine (cast after '76) with a manual transmission because it had a forged shot peened and flame hardened crankshaft, and adjustable rockers with solid lifter camshaft (up to 1980). They HD crank isn't really necessary for a mild build, though, it's more of a boosted application deal.
 
I like the short stroke 170's myself. Been driving cars with slants in them since 1974 . I still have 3 in service . They are good motors but if I wanted to be pinned back in my seat when I hit the gas I'd put an 8 in the car.
 
I agree that they do have their purpose. I just have not reached the point where I see a 6 cylinder engine adequate for what I want.
My 75 Power wagon is a 440 truck. The 67 Dart has a 360. My 70 Charger has a 440/493. My daily driver is a 2007 Ram 1500 5.7L.
 
They are good motors but if I wanted to be pinned back in my seat when I hit the gas I'd put an 8 in the car.
Very true! The most aggravating thing about the slant six is the staggered bore spacing. It makes it almost impossible to adapt a different cylinder head of any type to a slant six, and the point of diminishing returns is met very rapidly with the factory head. They are still a fun engine to play with! I once seen a late 70's dodge colt with the firewall moved back for a hilborn alcohol injected slant six with a piece of 2X4 zip tied under the gas pedal for a throttle stop to keep the car within its safety certification, and it was running high nines. With all the weight bias up front, I imagine it handled like newsprint in a windstorm...
 
My slant on slanties;
install some 4.10s, a 2800TC, and a free-flowing exhaust, and..... rock-on! Your slanty will take on a whole new vibe. Things go even better with a clutch. If you have to pick just one, make it the gears.
 
22 mpg and can smoke the tires, slant six is worth it to me. Mill head .100 bigger valves high lift camshaft headers gearing must be changed 3.23 to 3.55 and a stall converter dizzy recurve. Should spice it up.
 
22Hiway is easy with a 360 and a 220* cam;and can make close to 330 hp or more;and can go 106 in the Qtr, smoking 2 gears with 3.55s. Heck, I got a recipe that made 32mpgUS, point-to-point, with that same combo,plus overdrive. Admittedly it cost a bit more to screw together, but I had a lot of the parts lying around.
My 9.5Scr 1980 Volare A/T, can't touch that. I like that F-body for one thing, besides it's handsomeness....... I'm trying to remember ; what was it again?........ Oh Yeah; it survived three student drivers, and 24 years that I've had it. No not on the original powertrain,not even close,lol. Ima mechanic; I fix stuff.
 
Hell, I had a 68 Cougar with a 440 that would run 10.80's, cost less then $3,000 to build. I say "so what". The OP did not ask about "which engine is best", or which "swap is easier/cheaper", he asked about modifing a slant six.
 
I guess somewhere along the way we need to ask what this six will be going into and what it’s intended purpose is going to be. Most importantly though, what is the OP’s budget? In a naturally aspirated application if the budget allowed for it, I would consider going with an EFI such as affordable fuel injection.
 
22 mpg and can smoke the tires, slant six is worth it to me. Mill head .100 bigger valves high lift camshaft headers gearing must be changed 3.23 to 3.55 and a stall converter dizzy recurve. Should spice it up.
Sure but;
I see that as a recipe costing about $6500 plus whatever labor you can't do yourself.
1) engine freshening; the full meal deal cuz you wouldn't want to tax a high mileage engine.
including valve job,milling,etc. plus cam kit,etc.
2) Hi-stall, plus installation. Might as well freshen the trans now,so you don't have to take it down again next week.
3) Rear gear swap with bearing kit.
4) other; header, free-flowing exhaust, intake and carb, and fitting it. Plus whatever need to be done to the cooling system, and the ignition system. Plus a monitoring system; tach and gauge pack.
Plus maybe some normal maintenance to the suspension steering and brakes,etc.

Since rear gear swap is part of this pkg, I recommend to just start there. You'll save thousands, and with 4.10s over 2.76s you're looking at a 48% torque boost at all rpms. There is no performance mod you can do to your engine, short of supercharging that will touch this. Even if you increased your engine torque 48% normally aspirated, you still wouldn't match the gear swap performance increase. This is because the engine mods will not equal plus 48% over the entire rpm range,like the gears do, but over some much narrower rpm range.
But to be fair, if you currently have 3.23, then the 4.10s are only a 27% boost, which you are still gonna have a hard time to match with engine mods alone.
Now;4.10s will get you 50mph @~3900 at the top of second gear, about where the stock cam power-peaks. To match that performance with 3.55s, you are gonna need a boatload of power increase, and the new cam won't peak in second gear until maybe 70mph. At 50mph@3360rpm, the higher-cammed engine will be tortoise-slow comparatively speaking, some 1500rpm short of the power-peak. So now, maybe it smokes the tires with 3.55s pretty good, alrightee... but top of first might be 5000@ 44mph; then comes the shift and the Rs drop to 3000, and that's that.
Of course with 4.10s the Rs will drop as well, and with the stock cam you might be shifting outta first 600 rpm sooner so that will paint an even worse picture. Say you shift the stocker into second at 4400. With 4.10s this is now 34mph. The Rs drop to 2600, perhaps a little under the torque peak, I call that almost perfect. Because at 34mph, there is now waay less wind resistance,the slanty with 4.10s is just gonna keep on charging all the way to 50@3900
2.76s to 4.10s is a huge jump, and the first time you open up that big single barrel,lol,you won't believe it's the same car.
I've done this to a few smogger-teens with 4.10s and 4.30s, with fabulous results. Even leaving the the rest of the combo dead-stock. Of course most of the guys went on to other bolt-ons eventually.

Anyway, that's my take on saving something like $5500 smackers.
 
This is good input, so here is the rest of the "plan". Late '70's Dodge P/U, shortbed, w/ hotrod /6, 5-sp Tremec, 8 3/4 rear. Stock frame but independent front suspension and coil-over rear. Keep it as much Mopar as possible. OK- now you can go crazy.
 
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This is good input, so here is the rest of the "plan". Late '70's Dodge P/U, shortbed, w/ hotrod /6, 5-sp Tremec, 8 3/4 rear. Stock frame but independent front suspension and coil-over rear. Keep it as much Mopar as possible. OK- now you can go crazy.
How do plan on using the truck? Sounds like you have a decent budget. If planning on using it as a truck (to haul things) Then I would consider swaping to a V-8.
I Have a 1984 D-100, slant six, super six conversion, A-833OD trans, 3.91SG 8 3/4 rear, A/C
Haven't had for very long and still need to make improvements. Get upper teens, running empty, and got 13-14 mpg towing my race car to kentucky and back from Florida. It did OK, but could use a little more power for long grades, or steep hills. Biggest problem I have is the clutch (not uncommon with a slant, as they have a small clutch) . Really have to baby it. I don't know it's actual condition, it could be just about worn out, or possible oil on it as the rear main is leaking. As soon as I have time, I will pull the engine to reseal, and install new clutch.
PS: I also have a 88 D-150 fully loaded, with a 360 4bbl/727. It pulls just fine, but gets about 9 mpg towing, and 10 empty.
Choose your poison.
 
You're right, while I don't have "deep pockets", this is not a budget build. This will be strictly a little hotrod, a clean street machine, a semi- show truck. It must have the correct lowered "stance". OK, so what would you boys do if it was yours? Still want to show off that little /6. And I do like to drive my cars.
 
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