New F1 1979 mod version 1.2

[gorgias1976]

no it won't i get an error message when the game tries to install the mod

Try going to Content manager at rFactor2 first screen.
There uninstall both the 1988_JEREZ and all SR4L_1979_LEAGUE mod you may find.
Go to the package folder shown below on that screen and delete those package files if still there.
Download them again from the race announcement post to the package folder and try rejoining the server