I have a 67 mustang with a 200 engine--I want to replace it with an 4.0 engine.

It will fit like a glove, a set of new motor mounts and you will need to beef up the front springs and socks...

Keep the old engine and transmission as the car will be a lot more valuable with all the original parts. If it were my car I would hop up the old 6 a little.

At least a 289 would be "original" but not ORIGINAL if you know what I mean. It is way too easy to determine how the car was built at the factory. I would never buy a classic car that had been kluged with an incorrect engine. The trans is not as big of a deal but still in today's world, originality is everything.

Did the 67 Mustangs with the 6 have the 4 lugs wheels? If so you would have to deal with that as well.