Absolut, you haven't mentioned whether or not your car has the under-hood insulation kit (have you looked for it yet?), which was (if it was installed at all - my 70s models never had anything but the underside of the hood's sheetmetal) a rather poor affair up until around '86 or newer. (I had an '85 with a fibrous/cardboard type of shield, which wasn't much use for anything except soaking up oil and grime.)

My '93 has a metallic-faced foam kit from the factory and IMHO it is a world apart in improvement of noise suppression from previous types of underhood insulators used on 240s. I can actually hear people talk and/or the radio in my car!!! ;-)

Sounds like your best bet might be to check to see if you have any kind of insulation and if not, get the insulator panels from a late model 240, and modify them with an Olfa knife if necessary for a good fit! Good luck!