Taurean Bull is WRONG about the transmission. The GM Turbo 400 is a 3 speed trans and takes lots of power to turn it.
If you can find one, what you want is a 4L60 Turbo. This trans is a 3 speed with a 4th gear OD and a lock up converter. You DO NOT want the 700R4 (dating from around 1980 up to around 1987 or 88)turbo, this is the weaker trans, and is the early version of the 4L60. The 4L60 came in Chev cars dated from ( I believe) 1989 and later, up to around 1991 or maybe 92. After that the trans became the 4L60E, the electronic version of the 4L60. This you also do not want as it requires an ECU to operate it.
There are good and bad reasons to us this trans.
A better choice weight wise and cost taking less HP to turn, but still a 3 speed, that would be the Turbo 350.
Chadbourn Bolles
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