Wondering what folks know about the differences in Cam Shafts in the XK8.

Ive seen examples of Cam Shafts that have different numbers of "lobes" on the rearmost section of the intake cam, at the rear end of the shaft, where the cam shaft sensor gets is readings and signal values.

Issue is, I'll see a Cam from say a 98 (where is says fit is for 98-02) with one (1) lobe at the rear of the shaft, then I see another where there are four (4) lobes,,, all being described as fitting the the same model years.... What am I missing?

 

The AJ26 has ONE lobe on the 'B' bank intake cam.
The AJ27 has FOUR lobes on BOTH intake cams.

 

Perfect. As always Bob, Thank you.
Clear and too the point...
Gives me some work to do...

I could tell ya a long story about my dumb moves,,, but I'll spare ya...lol