Yes I believe actually the 1986 to 1992 Volvo 240 4 doors are all interchangeable parts but I'm not sure for 1985 and earlier models.
Yes
1 to 4 , front to rear
Not 100% sure about the '87, but there is no PCV valve on the 1986 Volvo 240 2.3L. Flame trap and Oil trap, but no PCV.
Dextron D/M
No, they are not user serviceable
Yes. They are exactly the same as long as the newer wagon is also a 240 (not a 740). All 240 hoods are interchangeable from 1986 on.
Call Crutchfield. They have the installation kit, diagrams and instructions.
long answer: yes
Intank fuel pump and/or airflow meter also break system check valve.
Yes the 240 does have fuses. Was that your ?.
how do adjust timing belt on a volvo 240 DL ?