Been there. The block is 2 inches longer. You will need to move the radiator forward, and fabricate new front motor mounts. there will also be zero clearance at the firewall, and you may have to beat on the firewall a bit to make sure the engine doesn't actually rub.
You will end up with more weight, forward by 2 inches from original which can make a small difference in braking, steering, and handling.
If the 265 is free, and your time is "free" why not? But if it's for horsepower, just make the 217 into a 230, and up the C.R. and you'll have the same horsepower.