Fyi: I know starting in the 1983 model year, there are two original manufacturers of the evaporator box . Siemens and Behr. The evaporator itself do not interchange between the two brands.
Before you order an evaporator, make sure you check to see which manufacturer you have. I made that mistake, ordered a brand new evaporator for a Behr box and it didn't fit my Siemens box. I ended up getting a whole box out of the wrecking yard and another evap from a forum member. I used wrecking yard one and kept the forum member one as a spare.
Btw- the Siemens evaporator core is about a 1/2 to 1 inch wider that the Behr core.

.

__________________
1983 123.133 California
- GreaseCar Veg System