sounds good to me bro...
If you are gaining fat and muscle at a 1:1 ratio... its something in your diet (atleast that what it seems like to me...)
Whats yuor current body fat at, and what do you want it to be?
If you are 170lbs and 6ft tall.. you should be relatively skinny... Maybe you tend to be a little more carb sensative like me.... I am similar to you in that i gain both fat easily and muscle is difficult to attain. I can shred up pretty quickly if i want to by lowering my carb intake to 100 grams or so... But my strength does decrease a little aswell...
I noticed i gained my best results when i would cycle my carbs and cals... On my "heavy days" (i.e. chest, back and legs) i would "carb up" prior to working out. Intake about the amount of carbs you do on a daily basis (that you've listed above)... on the other days, i would taper down the carbs, and one day a week i would have a "LOW LOW carb day" which for me meant about 5-75g... This cycling of carbs and cals tended to keep my bodyfat pretty low AND helped me to put on decent gains.
Ultimately.... tweaking your diet for how best fits YOU is gonna work. Know how many cals and carbs and protein your intaking... and adjust it on a 2-3 week basis... seeing how your performance and weight (i.e. muscle bulk) changes throughout the weeks. 3 weeks is about enough time (in my opinion) to see if the diet you're on is "working" for you or not....
Give a couple differet diets a shot and if you're THAT worried about fat gain, do some light cardio a few times a week while maintaining your current diet....
Hope that helped....