I have frost plug leaking in behind my starter just wondering what most people are doing? Changing them out or is there somthing I can add in my radiator?

No you need to change it. I would change all of them at once. Trust me if it is leaking around it she is getting ready to blow fluid all over your engine compartment. mark

I changed one on a 454 just this week.
It wasn't too bad tapping the new one in there with everything still installed.
$2 in parts and it's fixed right

All the other core plugs have been bathing in the same corrosive coolant.

Change 'em all.