454 SS Transmmission not real 454 SS

[PapaGrune]

I am going to look at a 88 single cab, short bed where they pulled the engine to rebuild. They never got around to it. 5.7 he says. Transmission still in truck. I have a good, less than 100k miles mile 454 and th400 in my dads 74 GMC It ran till 6 months ago, needs tires and aa battery. Looking to put into the 88
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If the transmission is ? 700r4 maybe ,