In Reply to: Ford NAA verses ford early 2000 series posted by Will on August 28, 2017 at 00:48:43:
UD has given you good advise below.
I will add that the HP is similar between the two. 32 PTO HP for the NAA vis a vis 34 for the 4 cylinder 2000, IIRC. The increase is due to CR and/or RPM.
Both tractors have dry drum brakes but of different design. The NAA uses the same brakes as the 8N while the 4 cylinder 2000 uses the same brakes as similar Ford tractors built between 55 and the mid 60s. Both work well if in good condition and not oil contaminated but the later design is generally considered to be an improvement.
Myself, I would consider the 4 cylinder 2000 to be a noticeable upgrade vis a vis the NAA but would look for an 86/7/8 series or 4 cylinder 4000 in order to get the bigger engine.