160 to 190 makes about 3-5 lbs spine difference for me and my longbows in the 50 lb range. You will definitely lower your dynamic spine going up 30 gr in point weight, how much seems to depend on shooter, bow, draw weight and arrow length. It would take MANY hours of paper tuning with several shooters and combos to come up with really close values for different specs.
The Stu Miller arrow computer says you can use brace to tune arrows. I like my brace where the bow shoots best and quietest. I work with spine, arrow length and point weight to get my arrows flying right. Paper tuning is my method of choice.