I was running an old 1980, 1480 for 22 years and upgraded to a 2188 this last spring...like going from a Jeep to a Cadillac. I'm sure a 2166 would be quite a bit bigger than your old 1440. Basic wearpoints would be the same...not a whole lot of changes in Rotary technolgy since the beginning. Good Luck!
We went from a '82 140, to a '89 1660, to a '99 2366 to a '02 2388. You'll really like the 2366 over a 1660, more power better cleaning & a lot nicer cab.
Ran a 1063 on the 1660 & on the 2366 the first couple years we owned it then moved up to a 1083. Combine handled the 8 r head fine in corn up to & over 200 bpa. Ran a 25' 1020 on the 66 in beans which was maxed out in green beans but could've run a 30' after a frost.
Biggest reason for going to the 88 was to gain capacity in beans, moved up to a 30' 1020. Didn't think we would see much improvment in corn because of the ability to move corn away from the combine but did.
This year we replaced the specialty rotor in the 88 with an AFX and was really surprised at the increased capacity. Right now the heads are the limiting factor. Looking at upgrading to a drapier platform for next year but not sure whether to stay with a 30' or go up to a 36'
Like others have posted. if possible go up to an 88. I don't think you will regret it. If I had to do over again we would have bought an 88 like my son wanted instead of the 66.
The only con we have seen is that the sheet metal (clean grain elevator & auger meta) and unload augers seem to wear out faster on the 66 & 88. Seems we are replacing these things at 1100-1250 sep. hrs instead of the 15-1750 hrs on the earlier combines. But that may be because we are putting more grain/hr thru them.