Anything I should do to engine while I have it out on a stand?

[avid]

The 4.0 is a bit different than most OHV engines in that the pushrods are solid and don't send oil through them to the rockers. The rockers are oiled by separate galleries from the lifters. The plastic cup is there to retain a bit of oil to keep the bottom of the pushrod lubed.

Usually the wear happens on the top of the pushrod at the rocker, but since lifters are available and it's a roller setup I'd probably replace them.

Four of the twelve lifter cups were no longer attached. I don't know if they were old ones or cheap replacements. Also the valve stems are different lengths. I haven't dug up the specs yet but I suspect that's not good either. The engine was rebuilt by PowerTorque and only has 35K miles on it but is about 7 years old now. I should have inspected it more when I got it rather than trust.

I think I'm going to try to clean and use the lifters that came out of the Mazda engine I'm replacing. Found an instructional video on youtube for that:

 

[gaz]

@avid
I would use functional lifters that I had on hand too. In regards to the push rods/rockers...this are the components that wear, which changes lifter preload, making noise.

"Delta Camshaft" of Tacoma Washington, they bought all the remaining hardened rocker cups and will make you a set (send them a core set for a reduced cost).
"Smith Brother's Pushrods" offers both quality OEM replacements, custom length and adjustable push rods.

Oil is supplied through the rocker arm pedestals, to the rocker shafts and to the rockers/push rods from the top. Improving this oiling is worth the couple of minutes that it takes ..)

 

[avid]

Is this difference in the height of the valve stems a problem?

 

[Mechrick]

It's common for installed height to be different between intake and exhaust. Run the straightedge across all of them.

 

[avid]

It's common for installed height to be different between intake and exhaust. Run the straightedge across all of them.

Thanks for the reply, Mechrick. I started a thread (4.0 Valvetrain) the 4.0 Engine forum to discuss these valvetrain issues as I thought it would be more useful there for future searches.

I did run the straightedge across all valve stems. But the camera only focuses on a small area at a time. I used a feeler gauge and posted the numbers in the new thread. They're mostly random differences in height rather than exhaust/intake specific variances.