If it's the Lucky aerial film that's called SDH400 in a new wrapper, iso160 is optimistic. I have a bulk roll and I'd say proper exposure might be as low as 64. It's fine at 100. I doubt pushing more would do anything except make it horrible.
Indeed. I bought a bulk of SHD400 and it begs to be exposed at EI100. Everything else is underexposure that requires a push development.