Assuming the Tren you're using is dosed proplery, then 50 m EOD (175 mg/week) is compleely fine. In my opinion, 150-175 mg/week is an ideal dosing range to start with. I am currently using 40 mg EOD (140 mg/week) and I have been using AAS for years. Remember, you can always adjust upwards if you want, but starting with a large dose is a near gautanteed way to end up with harsh side effects.
However, I do think 5 weeks is a bit short for an injectable cycle, even one which includes tren. It is possible to runa 5 week tren cycle successfully...and you may end up wanting to come off after 5 weeks if you experience side effects youdon't like, but is the sides are acceptable to you, the 8 weeks is pretty normal.
Also, I would change your injection frequency with the test. It is true that 2X weekly is normally fine with a longer estered testosterone (I prefer at least 3X weekly, myself), BUT...keep in mind that you will already be injecting Tren EOD...and with plenty of room left in a 3 cc pin, why would you inject your test only @ 2x weekly, when you could just add the test to your tren pin and inject both EOD. Not only will you get a more even blood levels, but you will minimize the total number of injects, as both compounds will always be injected together.