Well this is a really big job to replace the head gaskets. And that is if the heads are ok on the motor. The head gaskets used on a V6 626 motor are a three piece steel gasket, so a cracket gasket might not be the problem. You may have warped a head. Sorry to be the bearer of bad news on that matter.
Removing one head is just as hard as removing both heads on this motor. Ie if you do one, might as well do the other. At this point it might almost be better to find a good low milage used motor and put it in. Might cost less for the labor and engine than pay 5 hours to remove the heads and find that the castings are no good.
Cosmo. Mazda TEch
Wednesday, December 20th, 2006 AT 12:01 PM