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Depends on a couple of basic factors... who is doing the disassembly or reassembly? Required machine work is determined upon inspection and measurement.. could just require a ball/hone... could require boring. Dunno.
For DIYer, Budget at least $1000 for machine work and up to $1000 for parts... oil pump, water pump, bearings, seals, a cam n lifters, rings, maybe pistons. Depends.
I had my last one bored .080" over for $150, but that was a buddy deal. On top of that I had pistons, rings, cam, lifters, bearings, seals, head gasket set, and a lot of my time. I had Delta make me a mid range torque cam (slightly higher lift and longer duration than stock), and was quite happy with it.
In your case, I would get the internals of a 300, or just rebuild a 300 to drop in. You will need a block from 86 or earlier, in 87 they made some changes including removing the z-bar mount and the mid sump dipstick hole. Your engine can be made into a 300 with crank and rods from any year 300, and pistons for a 65-73 300. As a bonus with that 240 head on it it'll have higher compression and give better performance.