[tractor8100]

I know you say it is a 1992, but which engine does it have, the 359 or 414?

Can you do the work yourself, or will you have to hire it done?

Unless you steal an engine (i.e. get it really cheap, don't actually steal one, and I put this in here because someone on this site will really think I am telling you to steal it) and do the work yourself, listen to markat425.

 

[tractor8100]

I will change my tune.
I was thinking $25-30,000 for early 90s 9400s, but thecombiner is right. I did a quick check on Tractorhouse and you would be lucky to get 92 9400 in good shape/3100 hours for under $35,000.
If it is a 92, it should have the 414 engine. If you can switch it all out for less than $15,000, it should be an ok deal. Finding the engine may be the tough part.

 

[tractor8100]

First, verify it is a 414, it should be.

That is a popular engine in the 7000 series tractors and used in the 94x0 walker combines and then the 9550 walker and 9560 and 9570 STS in multi valve versions. There should be some around.
I suggest calling Abilene Machine:
1 800 255 0337 Solomon, KS location
1 800 866 1504 Belmond, IA location

Their website is www.abilenemachine.com/

Since you have access to a shop and help, it certainly is worth looking into.
Also, just check with your local dealer, you never know what they might have laying around, or may be able to source one.