tdc

I got the first cyclinder on my 1986 mazda b2000 to tdc on the compression stroke the crankshaft notch and pointer line up the rotor lined up with the #1 spark plug terminal but the cam shaft is on C instead of A. Can anyone please tell me why?

A is factory set.
B is a few degrees advanced cam timing. Slight increase of power at lower RPMs, but loss at higher RPM.
CX is a few degrees retarded cam timing. Slight increase of power at higher RPMs, but loss at lower RPM.

Can I simply just remove the timig belt and turn the cam to A?

No, you have to remove the cam gear bolt, and reindex the gear.

I removed the distributor already do I need to put it back on?

Not to index the cam gear.

I guess I should let you in on what im doing or I guess you can say attempting. Im trying to get to the head gasket which i believe needs to be replaced because my truck became hard to start one morning and was smoking a lot while i accelerated and which never had happened. So i drove back home right away and the tuck sat for a day and then i drove it to a buddys house to have it checked out but it became worse and he just said there was oil in some of the cylinders and to drive it for a while to burn it off but just on my way back home in 5 minutes it turned off for the first time and didnt start back up. I got it home the next afternoon and checked the oil again and it was creamy and discolored. And when I took off the exhaust manifold there was coolant sitting at the bottom.