No, there was never a V8 or a manual transmission in the 929.

The 88-91 929 came with a 5spd manual, but only with the 12v V6 engine, not with the 18v, and its very rare.

the 929 was the lux MAZDA line, and in the US we are fat lazy fucks and we don't want to shift a nice car, so we are a "D" nation, not into clutching it up.

the 929 sohc v6 manual transmission bolts up to the 929 S making it a nice candidate for a manual swap.