Going through security at T8 at the 700pm hour without TSA-Pre is no bueno. I'd allocate up to 45 minutes for security at that hour...perhaps you'll be surprised on the up side.

Going through immigration and customs...I haven't been through since Covid but with BA now sharing the facility, I would expect it to be 30-75 minutes if you don't have Global Entry. Once through Security you can get to any gate within 12 minutes or less.