Originally Posted by Jake_Dragon
The builder looked at the numbers on the front pump and told me it was an 86, I couldn't find the number on the side of the case that told what year it was but his shop was full.
Date on the front pump is a casting date and can be YEARS before actual production use though in most cases is only about 4 months prior to use. The pump body where the number is can be used for auxilliary and non-auxilliary applications, so could even be used before 86 if someone want to use it.
The stator support (back part of pump) cannot be used in prior applications.
Your transmission has an auxilliary valve body which was not used before very late 1986. That case will not work for a non-auxilliary application meaning that it cannot be used in earlier applications.
Most solenoids in most transmissions have a date stamped on them. I don't know whether the 700 solenoid has a stamped
number or not. It does have a partial part number cast into the plastic, but that does not tell us the year.
Assuming that is the original pump body, your transmission is most likely 1987. Short of getting the build code, anything else is an educated guess.