[Hazex]

My furnace stopped working the other day and had someone fix it. He replaced the nozzle and the primary controller. Furnace is working. I don't know much about furnaces. But I heard that you are suppose to put the exact same nozzel back in.
Now.
He took out .75 60W and put in a .60 80W. Is this ok?
He then told me that my burner unit was to big for my furnace and he had the one that was suppose to be on there and he would trade me. Is he telling me the truth, or is he tring to pull one over on me?
The furnace was in the house when I moved in.
I would like to thank you for taking the time to read and reply.
Spec.
Furnace
Lincoln Barriere Model: LOA105R Serial: D 2421-9 Burner listed on tag: Riello M3 Nozzle min:.60 max:.75 Spray pattern: 800W. Division of Keeprite Inc.
Burner on it now.
Riello Model:Mectron M5 Serial:T217T Firing rate: .75 - 1.50 Max nozzle size 1.25