i put new strings and cable on my legacy , and every thing is back to specs , the new string is a vapor trail , and i went from 70 # to 75#s. so here is the question , when i paper tuned it i'm getting a left hand tear , i cant adjust it out with the rest , are my arrows under spined ? ( G T 55 75 xts 27")

mathews legacy
vapor trail strings
trophy ridge rest

did you intentionally go from 70 - 75#'s, or is it a result of putting the new string on? i'm asking because... just because your cam(s) may be lined up doesn't mean your back in spec's., your ata can be long, your brace height short, and your cams can line up. if you didn't intentionally go to 75#'s something's off.

other than that i'd say yes, you may well be. were you saying your arrow is 27" long, or your draw length?

i planned to go up in poundage , my draw length is 29 , arrows are 27 , ata and bh are in spec

one way to find out for sure is to bgack the limbs back down to 70 and see if you get bullet holes
if fo you may want to try a lighter point when going back up on the poundage to see if that will get the arrow a little more spine.
which will also give you a good speed increase with both a lighter head and 5 more pounds.

from my experience with those arrows you are underspined, and that's exactly the tear i couldn't get rid of until i went to 75/95's. shooting 75# at 29 inches, yeah, maybe you could do it with magnocks.