Rocker Arm Identification

[Hydro-idi]

Hey fellows hope you all had a good weekend. Anyways, I know the 6.9 and the 7.3 idi engines have different rocker arm assemblies and have heard the 7.3 rockers are far better than the 6.9 ones. But I heard somewhere that the last year 6.9 (1987) may have these updated rocker arms.....Is this true????
I haven't had the time to pull off one of the valve covers to take a peak.
Also, one of these days i will be pulling heads off to mainly put some fresh gaskets in her. Is rocker arm wear common with these engines? Just wondering what all would be a good idea to just go ahead and replace while in there. I know the lifters, at the least, will be replaced when I tear into it. Thanks guys

 

[icanfixall]

We can't buy the 6.9 rockers any longer. The appearance differances are the 6.9 rockers had a metal bridge from the intake to the exhaust rocker and the pivots were made from a soft metal.. I think it was aluminum. Been a long time since I talked or saw one of those rockers. The 7.3 rockers differ from the 6.9 by the bar that keeps the two rockers together as a set. Its under the rockers.

 

[hesutton]

You can see the differences below.

New Melling 7.3 rockers. The Melling part number is MRK-650.

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Top

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Bottom

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The old 6.9 rockers were looking pretty worn when I rebuilt the engine and I didn't want to used them again.

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Heath

 

[Hydro-idi]

Thanks for the replies Heath and Gary. So I am guessing the last year of the 6.9 did not have updated rocker arms?
Wow those rockers are expensive when purchased brand new .

 

[dgr]

Did you check auto zone?

 

[Hydro-idi]

Yeah I just checked their website. Still $320 in total for rocker arms. Jeeze that's awful steep lol

 

[dgr]

Sure beats $450 elsewhere. It seems expensive but those look like they have some serious machining going on unlike a stamped v8 gasser

 

[hesutton]

Yeah I just checked their website. Still $320 in total for rocker arms. Jeeze that's awful steep lol

I paid $95.92 for a 8 "kits" to do the entire engine. They was just under $12 per cylinder...... AZ 's website had them with free shipping.

Heath

 

[Hydro-idi]

I paid $95.92 for a 8 "kits" to do the entire engine. They was just under $12 per cylinder...... AZ 's website had them with free shipping.

Heath

How would I be able to get a price like that? haha

 

[icanfixall]

When you buy rockers your buying both the intake and the exhaust as one piece. Your buying only 8 count pieces but actually your getting 16 pieces.

 

[Hydro-idi]

When you buy rockers your buying both the intake and the exhaust as one piece. Your buying only 8 count pieces but actually your getting 16 pieces.

Gotcha. I am just wondering where heath got that smoking good deal because autozone is selling one pair (both exhaust and intake manifold) for $40. Wish that was the price of all 16

 

[Wyreth]

Thanks for the replies Heath and Gary. So I am guessing the last year of the 6.9 did not have updated rocker arms?
Wow those rockers are expensive when purchased brand new .

Just re-did my valve cover gaskets a few weeks ago, my 87 had the updated rockers. Near as I could tell it was the first time the valve covers have been off this engine too.

 

[Hydro-idi]

Just re-did my valve cover gaskets a few weeks ago, my 87 had the updated rockers. Near as I could tell it was the first time the valve covers have been off this engine too.

Thank you sir. Hope there is a good chance my rig is the same as yours in regards to the rocker arms.

 

[jaluhn83]

To add to this, the updated rockers are very much worth the money. I've had 2 different engines where the aluminum pivots wore out and cause valve issues.

I also had a newly rebuilt motor blown up as a direct result of these crumby old style rockers. One of the pivots cracked just outboard of the bolt probably due to someone (most likely me) loosening the bolts unevenly. This caused the rocker to tilt more and more as the aluminum wore, eventually holding the valve open far enough to kiss the piston and eventually snap off. I did however managed to get 100 miles out of the engine afterwards even with the valve head embedded in the head sideways, a ~3/8 hole through the piston and severe cracking of the piston. Unfortunately home was 200 miles away and the skirt more or less disintegrated at about 100 miles. It was still running though..........

 

[5 oclock]

Question. How much play is normal for the rocker arm. I have one out of them all that jiggles.

Also how important is the 20 ft lbs torque spec.