Turbo swap?
 

Ok, let's start by saying that i have a N/A S5 91' Gxl modded into a Turbo II look for now. I'm looking to buy a S5 13bt with the tranny, ecu, long block, rearend, and rebuilt it with atkins master rebuild of 3mm and AGGRESSIVELY Street port it. If you ask, why am i doing this? My current engine is giving in, and i want to have a spare engine once i do the turbo swap and rebuilt this one. I will like to know is there any particular tuning that the 13bt will required once is rebuilt and street ported once i put it in the car because i heard from some guys that you have to tune it or else it will break. Also i will like to ask if anyone has a acrobat reader file *.pdf of how to remove the emission in both s5 NA and Turbo. I will like to get some advice in this topic.

If you are just running the stock turbo, then you can get away with standard fuel mods (larger pump, larger secondaries, S-AFC) and not worry too much. If you are upgrading the turbo or plan on modding the engine further, then full standalone is the only way to go.

Emissions removal has been covered about 6 million times. You will find several topics archived and if you search for "how to remove emissions" and variations on that you will turn up lots of info.

I will like to leave it stock with street port will i still have to do those fuel mods such bigger pump, injectors? I will do the modification after a break in the engine from rebuilt

Yep. Definitly need fuel mods with any kind of porting on turbo engines.