Parts for my 4300 were around $750, machine shop charged $300 and they magnafluxed the head, ground the valves and seats, replaced valve seals, shotblasted and cleaned the head, bored+honed the block, replaced the cam bearings, cork polished the crank and measured it, replaced all the freeze plugs and cleaned the block, replaced the wrist pin pushers and honed to fit, then wrapped everything in shipping plastic. They didn't surface the top of the block, which I would recommend having done because of the way this engine is made after what I went through. I did all the work myself so I'm not much help on estimating that cost. It is a lot of work pulling the engine. Fuel tank has to be removed (sounds simple doesn't it?) and the tractor has to be split.
Parts and machine shop charges should be around ~$1250 total. If I had to guess on labor for someone doing it in their garage, 120 hours?
Not a sleeved engine, repair sleeves are available though if you are beyond .010
I'm curious what's wrong that's prompting the rebuild?