return question

[CheckItOut]

House built in 1983. Open the return filter housing and the return plenum is not tall enough for the filter. So, the plenum is about 3" shorter than the filter. The plenum is installed under a stair well (no insulation) so it would drawl whatever air is under the stairwell into the return. This is not ok today but I have no idea about 1983. Just trying to figure if this should go in the summary or body. Thanks