Nozzle/Needle Value to use on Walbor LMT?

I just read a similar post on another forum. The question was not answered by anyone. Some of you professionals or others may know and can give some details on this one.

I just received a carb kit for an old Walbro LMT carburetor I wanted to repair. The engine it fits is a old 15 1/2 HP off an old Craftsman, I bought new in 1997. No,
I don't have the model number handy at this time, will have to look in the morning for it. Engine does not have a fuel pump.
The carburetor kit came with 4 nozzles/emulsion tubes. All 4 nozzles/emulsion tubes-have different size holes in them. I believe this is the main jet?
I had to remove the old nozzle/emulsion tube by drilling it and using a easy-out. It had been in there 18 years and not easy to get out.
I did check the hole jet size first and remember is was close to 2 millimeters. The tubes in kit appear to have that size and some down to close to 1/2 millimeter.
Also, kit came with 2 needle values for the float. A rubber tipped one and steel tipped one. The kit had no instructions off any kind, in it.


Question (1) : Which size nozzle/emulsion tube to use and the effects of using the wrong one on the engine? (Maybe better gas mileage?)
Question (2) : Which one of the float needle values to use? (My old one was rubber, but I would like to try the steel tipped needle value.)

Thanks! Everything else is running fine, thanks to everyone's help here. I am old and retired, so go easy on me...