inserts are your answer. they make inserts in a bunch of weights upto 50 or 100gr.

the important thing you gotta watch is arrow spine...throwing 100gr on an arrow matched with 100gr tip could easily throw your out of your spine..run the numbers and see how much weight you can add to the tip before changing the spine of your arrows and go from there...or if needed, setup your bow to shoot a lighter spine(drop poundage) or if possible trim the shafts and make them shorter to stiffen them up to accomidate for the spine change with more weight up front....

also, removing weight from the rear will help FOC. going to blazers or feathers, no lighted nocks or wraps or anything heavy back there will help FOC...