I bought a Z6 head for my d15 block to do a mini me. I've been struggling with the mechanical timing for days with the y7 cam gear and cannot get it for the like of me. Is there any way to tell if the head has been milled and how luch? I would assume this would affect the timing

 

Use the Z6 or B7 cam gear. Obd1 head on an obd1 block only needs the obd1 cam gear.

The 4.75 degrees you read about is the variance in the camshaft keyway between the obd2 camshaft and the obd1 camshaft.

If you were puting the D16Y8 head on your D15 block then you would need the Y7 cam gear as it would be the obd2 camshaft.

I posted the pics one day comparing the cam gears between OBD1 and OBD2. And confirmed with my adjustable Z6 AEM cam gear put on top of the Y8 gear that the variance is exactly 4.75 degrees.

 

Correction.....

There is a bunch of confusion out on the interwebs as there are many Write ups and not all of them are correct.

It's been clarified.....

The Z6/B7 (88-95) gear for the Y8 head mini-me
And the Y8/Y7 (96-00) gear for the Z6 head mini-me.

Of note, the UP will not be pointed up at 12 noon like it is on the stock setup when the cam is TDC. It does however fix the half a tooth off from the 10mm deck height difference between the D16 blocks to the D15 blocks.