taken from another forum
Minolta MC/MD mount register is two mm thinner than Pentax K mount. It's also 1.5 mm thinner than Minolta's AF mount, which Sony now uses, so MC/MD lenses cannot be adapted to Minolta/Sony AF cameras either. Not without a lot of pain and hacking on the lens mounts.
So ... to be succinct, don't plan on using your Minolta MD lenses on a Pentax body. It's too much of a pain in the tookus. These lenses are sadly orphans now ... I used to have a full Minolta MD11 system and remember well how nice the lenses were.
You can use them on EOS and 4/3 System bodies, but even there I understand that the iris actuation lever needs to be modified as it interferes with the mirror on some Canon and Olympus models.
Godfrey