As I typed this thread, I remembered my grandmother also made sour cream raisin pudding. Very rich, and very tasty. From time to time I’ve searched for a recipe, but only come up with sour cream raisin pie.
Is the pie filling the same as grandma’s pudding?
Can’t answer your question on similarity Johnny, but would note that most recipes for pudding, mousse etc intended for pie/cake filling use more thickener than the stand alone to ensure the filling doesn’t ooze out of the pie/cake once sliced.
I’d scale back whatever starch/gelatin/eggs are called for by about a third for a smoother, non-rubbery texture.