(quoted from post at 09:40:09 02/28/18)
Less headaches and less expense to make a 2510 out of it with a four cylinder Dubuque engine . Belhousing and front motor mount re-work will be required .
If you go with a 300 series motor,
There is a JD 2510 Hydraulic pump support mount on e ba y. That allows you to bolt on the hydraulic pump indeed, but also the hydraulic support has threaded holes to connect to the frame rails. Frame rails are made of regular angle Iron, so you can easily make your own, or cut / reweld them as required.
For the bellhousing, you need to find a 4030, 4040 European, 4050 American, engine rear plate. 2510 or 2520 rear plate will not work on 3020.
Simplest way to go for the flywheel is to adapt the 3020 one on the 300 series motor to reuse same clutch.
Like said, simplest way to have a 3020 diesel is to put a Deere 3020D in it.
Cheapest way to have a tractor you can do cores with short term is to assemble your 2 junk ones together.
Most reasonable long term is probably to sell the 3020 and either fix the 4040 transmission or get a used one (maybe a quad range, even if it can take times to changes all the linkages and you have to make sure you get ALL the parts required in the salvage yard quote)
Also, your 4040 PS transmission core has to be of some salvage value. You can reuse your diff, 3 point, final drives.
If you do the transmission rebuilt yourself and use used parts where applicable, (like if you have exploded the planetary carrier, which will be hard to believe at 4040 HP...), the powershift is not going to cost you a lot of money to fix. It will sure take a lot of time.