Cranking your poundage up is going to make your arrow have different flight characteristics. The arrow is not leaving the bow the same way it was before you turned up the poundage. Any time you change something on your set up you might have to retune. Wether it is your head, poundage, different arrows, defferent rest, etc...

I use a NAP 2000 fall away and had the cable guard they sent in the package on my bow. I had very little vane clearance with that guard on so I put the original one back on and modified it to accept the cable. When I went back out to shoot the arrows impacted the target about 8" ' s higher than they did with the NAP guard on. I didn' t think it would have made a difference but the original cable guard pulled the cables a little tighter and 8" ' s was the difference.