I shoot almost exactally what you speak of.I shoot 49#@27 and my wood arrows are 50-55's 28 3/4"with 125gn points.They fly like darts.I just started recently with carbons.I got some carbon express heritage150's.First got them to bareshaft perfect with 125gn glue-on points,42gn long alumi glue-on adapter,anf the factory 12gn alumi insert.I will look again when I get home,but I believe they were cut to 30 5/8".My wood arrows weigh in at 512gn,the carbons set up this waty weighed 534gn.
Now I didn't notice until after I got them flyin good that some of the rest of the dozen were shorter.I ended up cutting 1/2" off of the length and changed the glue-on adapter to a 75gn steel one.They bareshafted a little weak,so I am going to try some broadheads to see what they say,if they say weak,then I'll have to cut a little more off,probably a 1/4".
I'll look when I get home and post up the actual lenght they were,I wrote it down.
Good Luck,
Mike