426 Middle Intake Valve Difference

[Ebs]

Got done assembling my head, I noticed the middle intake valve shows a different part number, I think I may have mixed up that intake valve with one of the other two during assembly.

Is there any way to tell them apart? Is it longer or shorter then the other two?

[grayracer513]

I believe it's shorter, but either way, one will be a significantly different length than the other two, and the difference will be great enough that there won't be any way to bring the vslve clearances into line.

[Ebs]

That's what raised the red flag for me, the middle valve has has no clearance, but I was able to shim the others into spec. To be honest, I was pretty careful to keep parts separate, but I'll pull the valves out and check the lengths for some peace of mind.

This is a used head I picked up and I didn't check the valve clearances before pulling it apart, that at least would've given me something to go off of.

[Brad_Aus]

I dont know about the 426, but on the later 450's, the middle valve has a ring/groove around the face of it, the outside ones dont

[Ebs]

Thanks for the heads up Brad. I took a look and that middle valve does indeed have a circle stamped around the bottom. The good new is I'm not getting sloppy and mixing up parts. The bad new is that valve is probably done for, even if I can get the clearance in spec it'll probably be with the smallest shim available.