New arrows bought. Now, what is the best way to get it up to weight?

[VAFarmer]

Okay,

Got some carbon arrow from Gander yesterday.  They are spined for 30-50 lbs, and are still full length. They are 7.8 gpi.
My recurve is 41 @ 28 and I draw just a little more than this.

what is the best way to tune at this point?

fletch 3 and bare shaft 3? then shoot to see the difference?

Also, who makes the heavier screw in broadheads?

to get to around 400 or 450-I will have to use around a 200 gr. broadhead.  Should I try to put most of the weight up front-or should I try some type of insert first?   I know each bow shoots different-but this is one of 1million or so supermag 48's.  
there has to be a 'generally speaking" in there somewhere-is it generally better to try and get all the weight forward, or to distribute?

Also, putting this much up front, this will change the spine some, correct?

Farmer

[Bowferd]

adding weight up front will weaken the spine. Depending on what length they are you could trim them back to stiffen them up a bit.
I prefer heavy up front but would tune them at current length and work with whatever weight is required to tune them in.
I usually work with just a couple bareshafts to begin with at 15-20 yds, and change my point weight 25 gr at a time until I have a feeling that I'm close. Then I fletch a couple and resume the tuning process.