Ive heard about the Chevy power book, but i dont have one

I need the dimensions to locate the accessory bolt holes in the cyl heads on the front of the engine

I have cardboard templates that are pretty close but wont be accurate

Here is a link that was handy but doesnt include head dims
https://www.thirdgen.org/forums/fabr...cad-files.html

Years ago I needed the holes in a pair of heads so I just put the bracket on with what holes that was there and took a drill the size of the hole in the bracket and spotted where the holes needed to be then got the proper bit to drill it out. It worked great for me but I have worked in a machine shop and don't thing anything about stuff like this.

Don't Drill Too Deep

I need them because Im making motor plates

The heads already have holes in them