With a OBD I scanner you can.
Yes
You can purchase driver window clips for a 1987 Chevy pickup at JC Whitney online. They offer free shipping with no minimum purchase.
owners manual.
Yes, this is possible. It could be many things.
On the fuel rail in front of your passenger side fuel tank or possibly the other side.
No a 1972 Chevy pickup is not the same model as a 1973 Chevy pickup. I believe it goes from 1967-1972, 1973-1980, 1981-1987. Doors will work from 1973-1976, 1977-1987. You would need to find 1972 doors as they are the only ones taht will fit a 1972. 1967-1971 are the same but there is something different about 1972 doors.
In the alternator
Johnsautoparts.com
Any radiator from a 1981-1987 pickup and as late as 1991 for the k5 and burb should interchange with minimal problems.
above the oil filter,to the left.
its located in the fuel tank