Re: Spey line for 11'-3" rod
Double handed fishing and casting is a lot of fun. Its great that you have decided to join in.
Following are some of my pointers. Sorry if this is not what you are looking for.
1. a 11'3" rod is on the shorter side for a good starter rod to learn spey casting. if you are nymphing or already have the spey casting fundamentals down, you should be fine. But, if you are just trying to learn spey casting I would move up to a rod around 13' length. Shorter rods demand a very precise timing and casting stroke, so there is very little room for error.
2. a 50+ feet rod would be too long for a switch/short spey style rod. A good caster might be able to make it work, but it is still a choir. Also, you would not be able to use this type of set up in tight spaces. Longer heads require bigger D loops. bigger D loops require a lots of space behind you.
3. In my personal opinion 520 grain is a loot of grain to cast with a 11'3" rod.
4. Would you mind sharing what is the make and model of the rod is. Also, does the manufacturer assign a grain window or WT designation?
5. I find Rio's scandi shorts to be a good choice for some switch rods. it has some sort of front taper and casts well in tight spaces. I personally avoid skagit system. too heavy and lack any sense of elegance that spey casting is known for.
6. Now, most of my comments are geared towards swung fly presentation. for nymphing, find the thinnest or lightest line that would load the rod and set it up as you would a long single handed rod.
7. Almost no shooting head would do nymphing and swinging efficiently. Some would do the job well enough. But, if you want to get the most out of both disciplines, get a dedicated swing set up (running line + scandi head + polyleader) or a dedicated nymphing set up. Having two different spools set up with each of these set up would do the trick.
8. I personally like the airflo lines because their coating is not made out of PVC and I find them to perform better over a longer period of time.
Hope this is helpful. Keep asking questions.