Hi @isocam. Changing the 'extent' of an ExtrudeFeature in a regular part is a very different task than changing the thickness of a sheet metal part. Is there a mix of sheet metal parts and regular parts that this code must work on? If it is a sheet metal part, then is its main/first 'feature' a FaceFeature, instead of an ExtrudeFeature? Have you assigned a consistent name to the parameter controlling that size in each part, or was it just left as its default, auto-generated name? Is there any specific 'from' size to look for, or a specific 'to' size to set them all to? Will you need to be able to interactively see the current size in a dialog and/or set the new size interactively with a dialog? Please provide more details about this task, and specifically what you want the code to do for you when you run it, possibly with a bullet list of steps.
Edit: Also, when you created those extrude features, how did you define their 'extent'? If they were all just simple, one direction (natural positive direction), distance extent, then that may be relatively simple to write the code for, but if the way the extent was defined varies, then that can make the code required a lot longer and more complex. There are several different 'sub types' of extents, and a pretty long Case statement may be needed for potentially dealing with multiple possible types, and their unique properties.
Wesley Crihfield

(Not an Autodesk Employee)