I'm not a Nordyne specialist, though it's nice equipment but I would see no problem with the substitution, provided the blower speed can be controlled. A larger coil (slightly larger) usually results in a slightly higher energy factor anyway.
If YOU want change, YOU have to first change.
If you are waiting for the 'other guy' to change first, just remember, you're the 'other guy's' other guy. To continue to expect real change when you keep acting the same way as always, is folly. Won't happen. Real change will only happen when a majority of the people change the way they vote!