I’m putting the original 305HO back in the Monte after taking the ZZ3 out for my Iroc project. This is mainly to make the car mobile but it may end up tagged with this engine for a while. Previous owner reported that this 305 has over 100k miles on it and has been out of the car since 1997. He said it smoked during startup and sure enough the valve stem seals were worn out. Hopefully this will fix the issue.