Just thinking outside the box today

It’s just something I’m kicking around now that I can do it. The heads on my duster have the heads in that I bought around 2005 used and damaged. I ported them in 2008 and they have been freshened over and over again and are on their at least 3rd engine of mine. I semi fixed a smoking problem last year (intake gasket) but if I get this set of heads I’m working on done I would like to update the porting on them and if the guides are bad kicking around installing 5/16 valve liners. Just winter thinking right now but I was curious if it’s worthwhile.