My 422 smallblock build

I had (probably still do but I haven’t seen it is fair bit of time) a right angle scribe I could sneak in there.

The NIB shafts I have are P4120589. The date on the box is 2002 but who knows when they were actually made. I have some TA shafts. Let me run out to the shop and I’ll see if I can find them.

The TA shafts I have are P357786 I think. The 8 may be a 6. Either way I believe them to be TA offset shafts. By offset I mean the oil holes not the mounting holes.

I’ll lay one of each side by each and see if the offset is the same. And yes, I’ll take a picture.




View attachment 1716296384

As the picture shows, the oil holes are in EXACTLY the location.

The upshot is the oil hole in the rocker NEVER EVER lines up with the oil hole in the shaft.

For the system to work the pushrod length must fit the Chrysler dimension AND when the valves are on the seat the pushrods and adjusters must get full oil flow and pressure.

My trusty machinist rule says the TA offset is .500. IIRC the W2/5 offset is .750 although I’ve seen some T&D rockers at .625 I think.

At some point in your program if you make enough power and rpm you will be forced to relocate the oil feed holes as I lined out elsewhere.

And I forgot to mention that I always mark each rocker for its location and then I know the hole in the rocker lines up exactly with the hole in the shaft.

If you get the oiling to the adjusters corrected you can run 360 on the seat, 1k over the nose and turn 9k. I know that because I’ve done it.

Until I see otherwise, any W2 shafts have the oil holes in the wrong location.


Thanks! It is a shame that Mopar did not relocate the holes. It would have been a simple operation.

It looks like I may have a winter project.

I agree with keeping the rockers where they are. I ended up with 2 different types of W2 iron rockers for the intakes. I bought/sold rockers from 3 sets to get equal valve lift on all cylinders.( within .005") I measured for every pushrod and so they too are cylinder specific. I don't have a lathe, so I cut them a bit long and then squared them up on the tipping side of the valve grinder.