There is no swap hardware to put the Z transmission behind a V8. It wouldn't handle the torque anyway. The 260Z engine is about 158 cubic inches, compared to 350 for a SBC. The old Z transmission bearings are typically ready to fall apart besides that, not uncommon even with the stock engines. It would probably last about one pull.
I haven't done it myself, but I wouldn't even try it just based on what I've learned.