Just taking off most of the big accessories will make the 478 much lighter.
Very true, I also went with the light duty truck water pump/ timing cover housing. This also requires elimination of the 3 piece timing gear drive and replacing it with the double roller timing chain & sprocket set used on 305, 351 & 379 engines, I was told there's less drag and really not necessary to have the gear drive on a light duty application no matter how cool a gear drive setup is. When doing this conversion you have to remove the center idler shaft which is has an oil passage that must be capped off with a 1 1/8 inch freeze plug or you will lose oil pressure
and for extra insurance make a steel plate cover to keep the plug secure