Did the NP203 change internally between 1974 and 1977?

[Silver Square]

The only shop manual I can find for the NP203 that goes into great and specific detail with step by step procedures with photos is this one https://ck5.com/forums/threads/np203-rebuild-guide.341563/ but it's for a 1974. Are the procedures and tools required the same? I've found all of the tools referenced in that manual, just want to make sure they're the same for 1977 before I spend $400 on them. I know I could probably do it without the sepcialty tools. But I've never done this before, and I want to have the correct tools required. I'll just sell them on when I'm done, or return them. Or just keep em. They're all Kent-Moore made in USA vintage stuff. May well be worth a fortune one day.

 

[75gmck25]

There were problems with the internal chain drive on early NP203's and they used a different width in later models. The info I found says:

1973 - 1978 --> 3/8 Pitch x 2-1/2 W x 98 Pitch
1978 - 1979 --> 1/2 Pitch x 2 W x 72 Pitch

I don't know if the difference in chain size would affect any of the required tools.

 

[Silver Square]

Well, mine is a '77, and so is the used case I got according to the tag on it. So if that's all that changed, I guess I'm OK. Now I'm concerned as to whether or not I should spend the $300 on a new chain too. I suppose that if I'm going back to full time 4x4 with 33x12.50s in the future, it would be kinda dumb to not replace the chain while I have it torn apart. This is turning into a very expensive proposition lol.

 

[75gmck25]

In the past they used to sell an NP203 chainsaver kit, but I haven't seen one advertised in a long time. I assume it just helped take out the slack in a worn chain, but maybe there was more to it.