In that pic with the caliper measuring the height, it looks to be 4.105", not 4.060".

I checked a stock 596 head I have here, and it's 4.110".

If yours is really 4.105", then they're likely going to need to be milled down more to facilitate the use of bolt on stands.

Ultimately, it's likely going to be cheaper to just have someone fab up some on-center stands so you can use std rocker shafts and rockers.

The w2 offset shafts are $150 each, and the stands are another $150.

By having the pedestals modified in this manner, it looks like the cost of the rocker gear will be higher than it really needs to be.