what size feathers should i get for my gold tips, 27.5 inch arrows and 90 gr heads?

No bigger than 4". You could go with 3" inch if you wanted or really any size if your bow is tuned right. I always go with 4" on my hunting rigs though. 5" on my recurve setups.

whats the difference in left and right wing feathers other than being from the right or left wing, which one is better>

RIght wing feathers MUST be used if you are fletching w/ right helical, and left wing feathers MUST be used if you are flethcing left helical. If you are fletching them straight, it doesn't matter.

4" would work very well w/ your set up.

4" rather than 3"

I use 4" LW feathers and they stabilize the arrow very well with my set-up.I buy feathers full-length and get 2 4" fletchings from each.If you have LW feathers you must use a LW clamp--RW feathers,a RW clamp.Other than that,it's just a personal preferance--one flies just as well as the other.

What broadhead are you using. If your using a mechanical, you can get away with 3", better yet, go to vanes or Blazers.

If your using a solid fixed blade head, go 4" feathers, I'd recommend right wing with a slight offset right pending your rest.

Ditto everything Rob said...

When I first started bowhunting years ago, I was shooting a 75-grain Rocket Aerohead Miniblaster. I fletched with 4" right-wing feathers at a slight offset with perfect results.

I use 4" feathers, actually I recycle the wing feathers of turkeys I shoot! [8D]

4" feathers are great. I use them on all my compound setups. I use straight offset clamps and still get decent spin.