So I was doing some routine maint on the duster this weekend (trying to figure out the rough idle) when I pulled the #1 plug only to see a shiny spot on the side of the tube. Does this sound like a bent pushrod? and what else should I look for if this is the case? I'll be pulling the valve cover tonight to see what gives.

Back story: It is a 73 /6 duster daily driver with a super six setup with a holley 2280. I haven't spent much time under the hood but now that it is back on the road I'm working through it. When I had the manifolds off, I found a plate stating that the motor was rebuilt at 60,000 miles, It now has 135k and I've only been driving it for a couple of months (short trip to work 4 miles)

Yes, it sounds like a pushrod is touching the tube.
With the valve cover off, run the engine and inspect the pushrods... they should all be spinning and you will be able to see a bent one.

Adjust the valve lash while you have the valve cover off, doing that should help smooth-out your rough idle.
DD

Thanks Doc, I've tried a multitude of things before I decided to pull the valve cover, I just needed to know it wasn't the carb before I got into it. I did the super six swap while I was in the middle of the bodywork so I haven't had a chance to tune it until now, and subsequently removed the carter BBD due to a worn throttle shaft. I want to say that I've done almost everything listed in the forums BUT valve lash. Also, I tested the vac advance and it's not holding vac, that coupled with the 2280 not having a port for the advance leads me to ask if I can modify the distributor for mechanical advance only?

Next question, Are ALL /6 pushrods the same length/diameter? This is a 73 with solid lifters and I was wondering if I could pull some from the local yard to get me going.

All 198 & 225 pushrods are the same length, 170 pushrods are shorter.

As for an all mechanical advance, it can be done but you would need a distributor that allows somewhere between 22 to 32 degrees of mechanical advance. (long govenor slots, 11X, 13X, 16X)

All mechanical distributor advance will never get the MPG that a vacuum advance set-up will give.
DD

DD you are the man, Took the valve cover off and #1 intake pushrod looks like a banana! and upon further inspection, one of the bolts that holds down the rocker shaft was loose. I guess the fact that the bracket that holds the transmission to the engine below the starter was missing two of the bolts was a good indicator that the shop or previous owner was a pole.

I suppose it would be a good time to do a compression check as now the whole motor is suspect...

Ok so I was in there tightening the rocker shaft bolts, and I figured what the heck, let's check the head bolts..... 3 were loose and I was able to tighten one with my fingers.... now I like to think of myself as "super"-manley but I digress..

Now the thing barely runs.. I suppose all of the rockers are too tight but c'mon it idles like a 440 with a wicked cam but has no power.. I'll set the valve lash and replace the pushrod tomorrow and look at it with a fresh set of eyes.

Whats the history on this motor.
Someone just had it rebuilt before to got it???

I think now that the head and/or the rocker shaft is torqued down, the valve lash is to tight, which would hold the valves open and make it run very badly.

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67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir

Just saw that your from Orlando. What part / zip code?
I am in 32807 around the 50/436 crossing.

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67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir

Bren67Cuda904, yeah I'm at 50 and the 408. I'm going to fosters or LKQ at lunch to pull a couple of push rods so I can get it done before Melbourne this weekend, you going?

The history of the car is sketchy at best, it started it's life in NY and made its way down to FL in the late 90's. The tag on the block stated that it was rebuilt by a company in New Jersey at 60,000 miles. from there it appeared to have a lot of electrical problems as there were 2 spare alternators, a few ballast resistors, ignition box and voltage regulators in the trunk. The pushrod has been bent for a while as there are 4 spots on the tube where it has been rubbing. To say that it is running badly is an understatement, feels like it's going to vibrate apart.

Adjust the Valve Lash...
What are you waiting for?
Ask questions if you do not know how, it is easy.
Do you have a feeler gauge a 3/8 socket?

If you need to show yourself how tight valve lash can make the engine run bad... loosen all the adjusters by 1/2 turn and see how it runs. (it will run better but some rockers may "tick")

When you tightened the loose rocker shaft and head bolts, this made the valves lash even tighter... the lash needs to be reset to .010 in the intakes and .020 on the exhaust valves..
DD

why bother for used push rods-- autozone or the like should have new ones for approx $2.00 each-- anyhow they had them in Wichita ks. If

your head bolts were loose-- I would check the torque on all of them-- you need a manual--- but basically you start in the middle * circle your way out.. If they are way below the torque value-- you need to so this in stages-- say start at 40lbs then 65lbs (this is the head bolt torque from my 1964 FSM) Then do the valve adjustment listed on this site-- make sure not to confuse the intake & exhaust setting---

then check your timing/carb adjustments

Doc has pretty much done it all to a slant & his info is good(read the lastest Mopars Collectors Guide on the 62 valiant)

congrats on your slant it will be running smooth in no time, Lawrence

Doc, Thanks for the encouragement. Adjustment is first on the agenda for tonight. I now have the pushrods and a new set of feelers (old set was a little rusty from sitting 8yrs). I'm not waiting per say, I just didn't feel like doing it last night at 10PM. Before I tightened the rocker shaft it did have a slight tick but now it's REAL quite.

Lawrence, I didn't even think about autozone, doh. I went with the torque specs in the chilton's manual (70ftlbs head bolts, 25 for rocker shaft). and from the chart, 3, 7, 12 were loose and 3 was the scary one. As for the carb.. yep have to do it all over again as I've been fooling with it only to find the stuff wobbling around inside the valve cover.

I love slants, any other motor would be toast by now.

Not that there was any doubt, but at the end of the day all is good. Valves adjusted and the nasty stop light convulsions are gone. A slight bit of tick here and there, but I guess all slants sound like that. Thanks for everyones time. Hats off gentlemen.

Just in case anyone was wondering, out of the 10 that had to be adjusted, 9 were too tight and one exhaust was all together not closing