used motor $100 to $300, i wouldn't pay more for one
to rebuild (prices are approximate but to give you an idea)
parts
$150 pistons and rings
$80 main bearings and connecting rod bearings
$40 hydraulic lifters
$55 timing set (sprockets, chain, tensioner and guide)
$25 pushrods
$50 rocker arms, pivots and bridges (optional but i would do it)
$80 full gasket set (including front/rear crank seals and valve stem seals + all gaskets to assemble the engine)
machining costs
$150 for rebuilding the head
$100 cylinder boring and honing
$150 crank grinding and micropolishing
you could add Cam bearings to this as well, depending on the mileage you might have to replace them or not ($25 or so). Same for the oil pump, it's about $50 for a new one. Water pump will take you another $35, and i would replace the thermostat even if it's good for peace of mind (another $10). you'll also need some good black RTV ($10 or so). Depending on the status of your freeze plugs (expansion plugs) you might need to replace those as well, add another $10 or so for that (use steel ones if your rad is aluminum).
like i said, approximate costs but to give you an idea comes to about $850 on the low to about $1000 on the high for the hole thing if you take it apart and assemble it yourself.
