4.0L OHV 2.9 rockers on 4.0 heads. anyone done it?

[FildoDagginsRHEC]

I had read somewhere in this goldmine of ranger info that is TRS.com that "the only way to get ride of the 4.0 ohv valve tick is to get the heads milled to accept the 2.9 rocker rails.

now, I have brand new clearwater cylinder heads for the 92' 4.0 I have.
I also have [2] 2.9 motors 86' & 88' CA emissions and a 76' 2.8

has anyone done this? put the rocker rails from a 2.9 onto a 4.0?
anything specific I should look for in doing this?

 

[franklin2]

Installing the 2.9 rocker system is a improvement? They had and have plenty of ticking and oiling problems with the 2.9 also. Looks like the 4.0 receives oil on top just like the 2.9

 

[FildoDagginsRHEC]

I had read somewhere in this goldmine of ranger info that is TRS.com that "the only way to get ride of the 4.0 ohv valve tick is to get the heads milled to accept the 2.9 rocker rails.

now, I have brand new clearwater cylinder heads for the 92' 4.0 I have.
I also have [2] 2.9 motors 86' & 88' CA emissions and a 76' 2.8

has anyone done this? put the rocker rails from a 2.9 onto a 4.0?
anything specific I should look for in doing this?

I found the information I was looking for...

4.0L OHV Thread '92' 4.0 clear water cylinder heads and Elgin Industries rocker arms and push rods'

May 18, 2026

i had read on here a few months ago about clear water cylinder heads and elgin industries rocker arms and push rods that are said to fix the valvetrain tick these 4.0's develop. my question is, the pushrods do not have oil gallery passages running through them. (grew up building 60's mustangs with dad, 289's and 302's have the hole rifle drilled through them for oil.
i guess what i am asking is, should i call the manufacturer and request a return?

• FildoDagginsRHEC
• Replies: 6
• Forum: 4.0L Engines

user gaz suggested it. just like to see if anyone else has done it or has heard of this.

 

[franklin2]

If you read that thread more closely, he said the rockers from 86-88 are the same, he was just using 2.9 rockers because he had some laying around. Sounds like he was basically "blueprinting" the valve train, to get everything in spec so the lifters had plenty of adjustment. And also modifying the oiling for more oil flow to the rockers.

Ford and other OEM's have a tendency to throw things together at the assembly plants, calling it good enough. If the vehicle lasts good enough, 5 or 6 years, that is good enough for them, since most people do not keep vehicles very long before they buy new ones.

 

[SenorNoob]

Isn't there a kit (Maybe Morana) with adjustable rockers out there? Seems like that's be the best thing, but then you have another regular maintenance item.

 

[franklin2]

Isn't there a kit (Maybe Morana) with adjustable rockers out there? Seems like that's be the best thing, but then you have another regular maintenance item.

I thought they were already adjustable(at least on the 2.8 and 2.9). What is that little screw and locking nut I have been turning on the tip of the rocker?

 

[gaz]

@franklin2
The rockers used in the OHV 4.0 are non-adjustable. 2.9l adjustable rockers can replace them but 6 of the 12 will be out of alignment with the valve stems until 1 side of 6 are machined approximately 0.020" (please don't hold me to that measurement as each engine will present a unique offset).

Yes this is an improvement. The REASON that 2.9l valve trains get loud + tappy is due the lifter preload coming out of proper adjustment. Once properly adjusted, they sing the lovely, song of SiLENCE They will require adjusted approximately every 30k miles. Whether in a 2.9l or 4.0 OHV, the valve train can maintain adjustment over wear until unserviceable; resulting in optimum fuel economy (crazy RIGHT).


@FildoDagginsRHEC
I recommend using new 2.9l rockers. Last time I bought a set they were very well priced, I used Manley's but a decent set of used rockers can still work. In my experience, they have a use life the equivalent of 120k+/- miles.

The "machining" adjustment could be performed with a dremel, cut off wheel or sandpaper with a block of wood, so long as you have the ability to make and apply the needed change.