You'll want the '85-'93, sourced from a full size truck, Caprice/Impala, or from an S10 with the 4.3 V6 option. All of those should work fine the available adapers. The '82-'84s should be avoided, unless a full rebuild is done first, including a pump replacement. The early 700R4 has a weak pump, and was known to lose pressure when in overdive. The later pump solves that issue. The '94 and newer (also known as the 4L60E/4L65E) are electronically controlled, and may not be desirable for use with an older engine.
