I am trying to find a way to put insulation in my basement. On my south wall, there is no insulation between the rim joist and the first floor joist. There is about a 7" space between the two joists. The rim joist sits solidly on the sill plate. The first joist in has about a 3/8" - 1/2" gap between the bottom of the joist and the foundation. I need to get insulation between the two joists. Any suggestions? I am considering buying many cans of spray foam, but not sure if that is the best option. Any suggestions?

That's a lot of cans. Why exactly do you need to fill in this 7" space that only has a tiny access? Can't you calk all around the exterior, stuff a little fiberglass along that 1/2" space, and just insulate between the rest of the joists with fiberglas the usual way?

Either that or hire a spray foam company, who might be cheaper than DIY.

Also, beware of insulating areas that might be prone to water seepage. Just rots a lot faster.