RE: Figuring out arrow weight
Your talking about CX300's I would guess?
If so they are 8.1grs. per inch and finished as you describe would give you a total arrow weight of about 355grs and about a 12% FOC.
Do yourself a favor and put bushings and large Groove "G" nocks in those shafts.....they are very prone to cracking with the stock press in nocks both from shooting stress and rear end hits. This will only add a couple grains over the stock nock and will make those shafts last MUCH longer for you.