Are you cooking or smoking? Play with your smoker or cooker and use temperature probes and see if you have any heat zones. Some places could be hotter than others.
I like to heat to 145 also and don't like cooking to 155 or 160 as many recommend BUT when cooking to 145 you have to make sure all get there and hold it for 3 minutes but I aim for 10 at least. Longer even is better as long as staying under 150 and you should stay very moist.
I don't use pork but use ground beef and you can use what you prefer. I use the 73% which is 27% fat. once mixed 50/50 with deer you drop to 13.5% fat and that is good. you can go higher, but I did 80% which leaves a 10% fat mixture and that is too dry.