I am not ready to do the conventional 360/727, so I am deciding on my plan of attack for the 225/904. I have an 8.75 with 3:23's (not yet installed), and I've got a SS cast iron intake, but no other parts. I have read all the posts on DDuals vs Clifford headers- I am still undecided. Clifford is local, and I can live with an electric choke. My biggest concerns are driveability and how to rig the throttle and kickdown linkage. I can tune a carter or holley, as long as there are jets, metering rods, etc available. But with the low compression, I don't want to overcarb it and have stumbling, etc. I am really wondering about the progressive Weber. But if I can get a complete SS setup with all linkage, that would be the easiest to start with. I have been watching e-bay periodically and have not seen more than manifolds- maybe I have just missed them. I am open to all suggestions and input. Thanks, Terry.

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NO WHINING and NO EXCUSES!

I run the Dual Dutra Duals, so have no carb heat. This is rarely an issue except during cold start. It will be very similar to cold start running with Headers. Headers tend to be a bit louder. If you go with Dutra's with the modified rear, you can retain carb heat, which is nice for a street car. As long as you can give the engine time to warm up, it's not absolutely necessary though.
Lot's of folks run Headers to good effect on the street. Headers will generally give you more top end power. The Dutra Duals seal up and stay that way. Done properly, headers can be sealed up for long term as well.

If your going to a supersix, you should be in good shape with stock compression. It would really like more, but it won't be a show stopper.

Going to even a small four barrel, your engine is going to want minimum 8:1 compression. It will be much happier with 9:1 or better. You will get more effect if you go to a bit more cam. Don't get hornswaggled into a hydraulic cam for a mechanical top end.
Without a lot of modification, the hydraulic parts will not work, no matter what anybody trying to sell you something says.
With a bit of searching on the subject, you should be able to find issues that folks have run into in this regard.

You can get a lot more snap for launches, and improve ET with more converter stall. Just depends on what your trying to do. I'm running a converter I got from 'Zilla. Stall is 2500 rpm, which was a tremendous improvement over the 2000 rpm stall converter I had on the engine. Running higher than 2500 rpm stall for street use may result in high tranny temperatures. With your choice of gears, I wouldn't recommend it.

If you decide to do head work, be cautious about hogging out the ports. Water is close. Cleaning the casting up is generally sufficient for street and even most track builds. Larger valves help quite a bit. There are a lot of options there. I went with 300 Ford valves which is over-kill for my build's operational rpm. I may retire that head next year and go to smaller valves.

CJ

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Part of Tyrde-Browne Racing

Clifford may be local, but there have been too numerous of posts questioning their quality and customer service to make it worth your while. You can get better products for lower prices by doing some smart shopping and machine work.

If you are after a mild daily driver, I would go with a Dutra front mainfold and a modified rear stock manifold. I would keep the two barrel Carter BBD. You should have a cable style linkage that will work with the Super Six. I would recommend a Lokar-style cable operated kickdown. These days a cable-style kickdown is cheaper and easier than tracking down a factory original Super Six kickdown.

You can take your current cam to a good cam or machine shop and have them regrind it for you. There are several cam profiles listed in the "Erson Group Buy" thread that have been reported to give good results. I had a stock cam reground to one of those profiles and it cost me $80 for a reground cam and lifters.

I would highly recommend taking the head off your motor and at least milling it to increase compression and getting a three or five angle valve job. Calculate your dynamic compression ratio with the cam profile you chose to get the best results.

Dual exhaust, a Carter BBD, a reground cam, and a warmed over head will really wake your car up. The 3.23 rear gears are about the best all around gears for street and highway driving. I think if you follow this recipe you will have a fun, powerful, yet economical combination in your Challenger.

Pictures are always appreciated as well!

I have a bouchillon performance kickdown coordinating the holley two barrel and 904 in my dart. I went with it because of the details manufactured into it and the fact that the lokar cable kit seemed very generic. I know people here have used it and that it is cheaper, but I still have to recommend the bouchillon kit. Only mod it needs is alteration of the supplied cad-plated throttle bracket depending on which carb you run.
See it here

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72 dart acquired 12/08 /6,holley2b, mopar perf intake, mopar perf header, cam, built motor,904 finally re-installed, 8.75....still needs sorting out.
99 dakota 318 5 speed reg cab picked up 9/09; Trans finally fixed! woohoo!

Guys- I appreciate the info- keep it coming. I have spent hours reading the threads and the matrix on builds. For me, Level 1 is exhaust with duals and probably a crossover or x, and the super six intake. Level 2 (next year) will be pull the head and proceed with milling, 3 angle, etc. What about hardened seats- is that just a given? I have not seen much about the seats. Will milling .080 or .100 be enough to make it worthwhile? At what point does rocker arm geometry become an issue? I guess pulling the head isn't that hard- maybe I should just go ahead and do it!

I have not checked for chain stretch- I could go ahead and swap cams and chain. Something like the Erson RV grind? Can it live with stock springs or do I need to change the springs when I do the cam?

Thanks for the info on bouchillon- a little pricey but if it works... incorrect throttle psi not only effects shift timing- it will smoke a trans in a hurry!

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NO WHINING and NO EXCUSES!

Welcome on the board. See this thread for kickdown options. Note you can replicate most of the Bouchillon kit with junkyard parts. In any manifold swap, it is very much worth your while to get the good gaskets for the manifolds-to-head and intake-to-exhaust junctions. Hard exhaust seats are a given on a head rebuild. Don't just mill any given number off the head; take the time to CC each chamber (sometimes there's more variance than desireable, correctable with an angle-mill) and measure your deck height and figure out how much to mill to get the compression you're after.

In the meantime, Tune-up parts and technique suggestions in this thread, and remember this engine will need periodic valve adjustment. See also Dutra Duals, and think about a good ignition upgrade.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I have not yet played with a Carter BBD, does it have jets and metering rods like an AFB? What can be done to "tune" the carb? Carb sites show several different Carter BBD's, some guys have stated they used carbs from a 318. There was a new carb in the classifieds, otherwise I go to pik-a-part and find a 318 carb, then deal with worn shafts and a carb kit, hoping someone before me did't lose parts or mix-n-match. Your thoughts?

BTW- I have petronix elctronic ign.

Thanks, TG.

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NO WHINING and NO EXCUSES!

On Craiglist up in Portland, there's a slant six 1970 Plum Crazy Challenger
for $15K... hope the future owner keeps it original...or plays with the slant just for fun and being different...

I expect the Challenger to be similar weight to our late A-bodies, so following some common advice:

1) Set up your intake and exhaust situation
2) Change to EI and get the distributor recurved (this can net both power and mileage).
3) The head being an early one, I'd opt for all the trimmings and hardened seats. To figure out what you need in the head...pull it and get us the deck height of the piston, most of us can do the calc with a Fel-pro composite head gasket and let you know how much to take off.
4) Pushrod length becomes an issue when you start taking off .100 or more on average, but it will depend on the CC measurement of your chambers on the uncut head (get a peice of plastic from Home Depot, and stop by the Farm store or Vet and say you need a Horse Syringe-the 60cc variety).RV grind is fine with the stock springs (I'm using stock springs with my Erson because the lift isn't much).


Good Luck,

-D.Idiot

The 318 carb is not quite right. Folks make them work all the time, but if you can score a correct slant six BBD, you'll be way ahead.

The Erson RV grinds don't require special springs. I run an RV15M RDP. Still haven't installed the 280!

Hardened seats came into play when? '71?

What's your performance goal with this particular build? How much city, and rural driving percentage wise?

CJ

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Part of Tyrde-Browne Racing

Factory induction hardening of the seats started in '72 on Slant-6s, '73 on V8s. This is not as good or durable as proper hard seat insert rings installed during a head rebuild.

A properly-built, properly-tuned 273 or 318 carb can run very well on a slant-6. The primary incompatibility is the choke lever (different for slant-6 vs. V8), which can be worked around without too much difficulty. The later BBDs with the raised-top float bowls have a step-up rod and jet system very much like that of the AFB, and with (IIRC) rods and jets interchangeable with AFB items. But:

1. You shouldn't need to do much of any rejetting unless you are operating the car at elevation substantially different from sea level, and

2. There's a rash of new "high top" and "low top" BBDs on eBay. They are Chinese copycat/counterfeit/"reproduction" carburetors. If you put one of these on your car, please also apply a warning sign on the outside of the car so I know to keep far, far away from it on the road.

3. The early carbs run well, too.

It's all down to carb condition more than anything. Y'want a good, cheap, new, readily-tunable 2bbl carb to put on your 2-barrel conversion? Get one of these new Holley 2280s, originally built as service replacements for '74-'78 318s in trucks. The seller's dependable—I've been buying from him since well before the internet—and the carbs are nice. Holley jets are very easy to get. The carb's new, not a "remanufactured" piece of trash. The choke and throttle shafts are Teflon-coated. There's an inbuilt throttle-return spring (as required on all new cars starting in '74) for greater safety. The choke lever issue exists, but again, it's not hard to work around. I'd put in an electric choke kit number 1232 and make a new pushrod for it out of carefully-bent brass rod stock of the correct diameter, to mate up with the V8 choke lever. My only beef with these carbs is they have no external bowl vent, just an internal one. This was a stupid idea on Chrysler's part, to eliminate the external bowl vent (thus eliminating the hose from the carb bowl vent to the charcoal can and saving a penny or three per car). This can cause flooded hot starts, but here again, if it winds up being a problem and you're motivated, it's not too difficult to fix. The external-vent parts can be robbed off a used 2280; the chamber and cover are present on the new carb so all you'd need to do is drill a couple holes and transfer the parts.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

The car is a weekend driver and cruise night car- it does get driven 80+ miles to some cruises and rod runs. Here in Southern Calif there is something almost every weekend if you have the time. The car is way too clean and original to build another small block car. I purchased it in 2008, it is all original with 107K and still has crayon marks on the valve cover. If the hood is up, people just stare. It has new interior, disc brakes, etc. Just needs an aggresive exhaust and a little more umph.

Back in the late 70's when I was in High School and working at a local machine shop I had a 70 Challenger with a hot 360/727/4:88's, etc It ran 13.30's at Orange County.

Re: the carb- I sent a note to Scott who had one for sale a month or so ago. Thanks for the help- gotta get off this computer now- TG.

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NO WHINING and NO EXCUSES!

The Holley carbs look like a steal at $75. Re: the choke- If I choose the Clifford header instead of DDual- has anyone fabbed up a bracket for the electric choke? Has anyone tried mounting an electric choke right onto the carb?

Stupid question- what is IIRC? Thanks, TG

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NO WHINING and NO EXCUSES!

The electric choke Dan recommends attaches directly to the carb.

What does IRC mean? Hmmm, I used to know, let me think.

If
I
Remember
Correctly

IIRC has something to do with what you remember.

The one pictured in the linked thread fits in the choke pocket of the stock exhaust manifold...

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David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

Not that I'm aware of, but it wouldn't be difficult. Beware Clifford; they're an unreliable vendor and the quality of their parts (and advice) is, um, "highly inconsistent".
Yes, but it's akin to travelling from Denver to Boulder by way of Topeka.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.