If you are happy with the way the gun was performing, I say just replace the springs to the same weight you were using. If you feel you want to experiment to see if you can squeeze out more performance, you should try a full length tungsten guide rod. Going from the GI to FLGR probably won't notice any difference, but the tungsten guide rod will add a little non-reciprocating weight out front which may help with quicker sight recovery. It is all personal preference, having a gun run the way YOU want it to run is all the reason you need to experiment with different parts.