It was making a similar noise with the 1.6 roller rockers, but it seems worse with the stock ones in.

I didnt check the preload with the stamped rockers, just torqued the bolts down to spec.

On the roller rockers, I set them initially at 1/2 turn after having what I thought was zero lash, then i adjusted them a 1/4 turn at a time, the noise didnt get better or worse, then I just swapped them out for the stockers. That is as far as I got.

I figured the stock rockers would take the variable of the adjustable roller rockers out.