i was wondering what grain of broadheads i should shoot with goldtip 5575s out of a 55 pound bow?

depends on your draw length, the arrow length and what it all does to your FOC. The easton arrows website has great tables to dtermine all that stuff. A 100gr will likely be good but you should check the website.

Yes it would help if we had your arrow length. Either way, I'll put in another vote for 100 grain heads.

Check out the archery programs like OnTarget2 or T.A.P.(the archery program). They have helped me out immensely and tell you exactly what you should be shooting. After using the programs I found out that I have been shooting an underspined arrow for the better part of 2 years! No wonder I could never get a bullet hole when paper tuning. Duh!

the GT website has an arrow builder on it that will give you an approx. of your FOC.

on the 100 grain field points what diameter seems to fit the best 11/32 or what?

11/32 are too big--go with 5/16 points.