I cut mine up in cubes like 1 or 1 1/2 inch squares............I just eyeballed it, not a tape measure. LOL It is much better to use the widemouth jars. You put the meat in the jar raw, then use a butter knife or spatula that is slender and pack the chicken somewhat with the end goal of removing the air. I went just to the neck starting and added 1 tsp of sea salt on top. I wiped the jar rim clean and then dry wiped. I turned the rims to just tight and placed in the pressure canner. It cooks it's own juice.
https://www.youtube.com/watch?v=fINnsFJGyKU
Follow the link above to the site for your altitude to find weight and time. It is really, really simple. Just remember not to open the canner or remove the weight before it cools enough to open or else it will draw it out of the jars. The jars will be boiling, so make sure the littles are not underfoot when you need to place it on the counter to cool.