Back to gym 3 years off.. Tips?

[ToTheBuckeT21]

Because of surgery, running a company and going back school at night I was out for a while, I'm finally able to get back in he gym after 3 years (Went back to school for nursing so no, I had zero time). Anyway, I'm starting all over at this point. I'm 5'11" I used to be 145lbs, worked my way up to 185 with about 3-4% bf and now I'm back down to 160lbs. I am the poster child of a "hardgainer". Since I'm starting over fresh I'm looking for any tips or changes to what I'm currently doing. So here it is.

Diet: pro shake in the AM and at night or after a workout. 3000cals day, 200g pro. I try to eat a ton of carbs early in the day. Since I'm a hardgainer I don't focus to much on what I eat, mostly how much I eat, but try to keep it somewhat healthy.
supps: right now just creatine, in a few months I might add a light PH, we'll see how this muscle memory kicks in.
Workout: for the first 2-3 months I'm just going to the gym once every 4 days. I'm focusing on compound movements and not even bothering with any isolation of smaller muscles like bi, tris, etc..
Day 1 - deadlifts, squats, bench (2 sets incline, 2 sets flat), shrugs
Day 2 - Back rows, pull-ups, military press
I'm doing this so I don't overtrain as I start, and so I don't hurt myself. In and out of the gym in 30-45mins. Once I notice some gains i'll add in isolation.

I'd like to be 170-175lbs by mid July with no bf gain, that gives me 3.5 months.. possible?

[Turkish Juicer]

It sounds like you know your stuff. I doubt many people will rush in on this thread to give you advices from left and right.

Concerning your question whether 3.5 months would be enough for a hard gainer with decent muscle memory to gain 10-15 pounds depends on your diet for the most part, I believe. I would start eating over the maintenance and increase the weights gradually to attain such goal.