Is there difference between MC for power vs manual?

^^Don't know as there would have been few cars in that era that were 4w disk brakes. It might be "sloppy" description on the part of the seller. There is a LOT of that going around with so called 'auto parts suppliers'. I would contact them and see if you can run that detail down

If you have the cylinder in hand, it is easy to confirm. Again, google residual valves or consult the shop manual. GENTLY insert a probe like a blunt nail into the ports, no valve you should be able to insert it an inch or more with no resistance. With a valve, less, and will encounter the rubber valve. Don't force it

master.jpg