Hey yall. Long time observer, first time poster… I have a 1940s cape in zone 6 that I am currently going through to air seal and insulate.

I’m at a loss as to how I should be insulating the spaces between the left and right interior / exterior walls. The total opening is only 8 1/2 inches… not big enough for me to get in and place foam board and air seal. The knee walls space is unconditioned and is vented as you can see from the exterior photo.

My thought was to dense pack under the floor, and the entire space between the interior / exterior wall. Not ideal since it won’t totally stop air movement, and it would be difficult to achieve 3.5 lb per cu. Ft., but would be a huge improvement from what it is now. But curious to get other suggestions.

Btw, the K&T is dead, so no worries to blow cellulose in there.