It may be your bow out of tune. 8 inches is a high brace height! I find most of mine to shoot the best at just under 7" recurves and longbows. Also to give an idea I shot bows in the 63 to 70 lb range with 2117 with a 215 gr snuffer on the front and that was off a 29.5 inch arrow. I would say 2117 and 2020 are way over spined for that light of a head. First thing I would do is lower that brace height start at about 6 1/2 and twist up from there and make sure you nocking point is set right I run mine just under a 1/4 inch nock high. I am now shooting a beaman 400 with a 215 grain snuffer out of a 55 @ 29 longbow and it shoots great. Personaly once you play with tune I would up my tip weight but you have to choose the broadhead you prefure and match your arrow from there!