GM switched them on/off depending on the year and emissions requirements. They did the same thing with their V8 trucks of the same era.
GM never sold an engine from factory with an oil catch can
Short answer is yes, long answer is it depends on the quality of parts you’re using, the scanner and your computer software. Have you tried searching cults3d or thingaverse or one of the other many websites with 3D files first?
Once you have the 3D model you can use the slicer to resize to any size you want. There are calculators online you can use to tell you what percentage to use for different scales