Pedestal mount replacing questions

I have old pedestal mount style Twisted wedge heads and I think the mounts are shot. When the engine ran, back in the jurassic era, it made all kinds of noise, like I've never heard before. It was definitely from the drivetrain and it would come and go as I would drive. Sometimes it would get really loud, almost like lifter tick, only like every lifter simultaneously and louder. I am replacing the lifter hold down (whatever that thing is called that looks like a spider) and I'm thinking I need to replace my pedestal mounts because some of them look flattened out at the tips. How do those come out? are they pressed in there? also, where do I get those? and last.. do you think I will be solving my problem? I have practically entirely new valvetrain going in including pushrods, lifters and rockers. The only thing staying is the valves and the springs and I had a valve job done and the heads cleaned.