You're right, Mikkel. There are a bunch of things to consider.
In your favor, cutting the trees in February while they are dormant will start you with a lower initial moisture content. Softwoods, being less dense than hardwoods also dry more quickly.
However, a total of about 6 months is not long for drying to progress in an 8x8 timber. The outside inch or two will be dryer than when you started, but there will still be a fair amount of water in the center of the timber.
Also affecting the drying rate is the relative humidity and amount of air circulation. Less humidity and more air helps, but too far in that direction leads to case hardening and surface checking.
Probably the best bet is to detail your joinery so that the timber shrinkage is hidden. Housing the ends of the timbers would hide the gap that develops as the recieving timber shrinks.

[This message has been edited by Grigg Mullen (edited 03-01-2000).]