I have my coils mounted to the “belly” of the block on each side where the truck motor mounts would bolt on. Works great for me and gives plenty of room for the downpipe at the valve cover. Only thing is now it’s a pain to pull the valve cover without unbolting the downpipe.
Any issues with heat down there? Mine are mounted in the same spot and I’m about to install a heat shield between them and the manifolds. The coils start to misfire on longer drives.