From your comments, you sound kind of new to the hobby, if I'm mistaken forgive the assumption. Here are some thoughts:
A 390, while the factory big-block option, is heavy, inefficient, and difficult to find parts for compared to the 302/351W.
A 302 and a 289 are basically the same engine, with the 302 getting the extra displacement through stroke. Newer 302 (aks. 5.0) are also the same, but some of the ancillary stuff changed (flywheels, accessory drives, oil pans, etc.).
A 351W is still a small block but a little taller than the 289/302. Since the '67 is a bit larger than the earlier cars and came with a big block option, the engine should fit but since it was not a factory option, you COULD have to look a little harder for mounts, headers, brackets, stuff like that. It depends upon what your car has.
A 289 HiPo is a rare animal, and in my opinion should be used mainly in the cars that originally had them for that reason. IF you can find one, it would cost you about double what a fire-breathing crate motor would, and you're still only getting 271 HP at relatively high RPM. A solidly built, reliable engine based on a 302 or 351 (you can stroke those all the way up to 427 ci if you're so inclined) will net you more usable power lower in the RPM band.
Good luck and heed the advice of other posters. Consider what your intentions are with the car and go from there. You are correct in that upgrading from the I6 will involve a lot of parts, so do it safely with brakes, suspension, axles, and steering components that can handle the extra power.