I got a quote back from my contractor this morning and he has proposed a 90 MBH input, 94% Lennox variable speed two stage furnace. I called York and they told me my old furnace was a 117 MBH input furnace that had an output of 88 MBH. They also told me that the furnace was a 70% furnace which according to my math would be an output of 81.9. This furnace seems to heat the house fine. If I do the math on a 90 MBH @ 94% that puts out 84.6 MBH. I am considering telling the contractor to give me a 100 MBH furnace which would provide 94 MBH?

With a variable speed furnace and two stages of gas heat I won't have any problems being a bit oversized will I?