final ohm load of these configs

8 subwoofers - Dual 4 vc series/parallel

8 subwoofers - Dual 2 vc series/parallel

i think dual 4 is a fianl load of 1 ohm and dual 2 is .5 but someone said something recently that had me second guessing myself.

That's correct.

8 Dual 4s wired in series to achieve an 8 ohm load per woofer.  Then those paralleled will yield a 1 Ohm final load.

8 Dual 4s wired in parallel to achieve a 2 ohm load per woofer.  Then those paralleled will yield a (.)25 ohm load.

8 Dual 2s wired in series to achieve a 4 ohm load per woofer.  Then those paralleled will yield a (.)5 ohm load.

8 Dual 2s wired in parallel to achieve a 1 ohm load per woofer.  Then those paralleled at the amp will yield a fire.