How much of a rebuild are you talking and are you doing any / all of it yourself?
Split them into three and starting adding up the parts / machining costs.
Top end / cylinder head
Valve guide? Valves? Valve seats recut? Any porting work? Are the Cams ok or do you want to change them?
Bottom end
New bearings and rings? Does it need a rebore and new pistons? Upgrade to ARP bolts? Does the crack need just polished or a regrind?
Sundries
Gaskets, fluids, new belts water pump etc.
As you can see there is a lot of variation and depends a lot in how much work the engine needs to rebuild it properly. The major things being rebore / regrind required?
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