i was just wondering since in tokyo drift, they put a skyline engine in the 67 mustang. Could it be possible for a newer engine such as the 2011 v6 mustang engine to go in it? and if so would the mpg be similiar to the newer mustangs? thank you!
Yes, it can be done. However since you even felt the need to ask a question like this I highly doubt you have the mechanical and fabrication skills to do any of the work yourself.
So may answer is, YOU can not put this engine in this car. But if you have about $50,000 to pay a custom car shop, YOU could pay someone to do it for you.
Personally, if I were to spend this much money on a swap like this I would not mess around with an anemic V6. Install the new 5.0 V8 instead. Ford now sells the 5.0 V8 in a complete crate engine that includes nearly everything you need to get this running in a car.
It wouldn't be easy or cheap. You would have to replace alot of things;
You would need custom motor mounts
You would need to do significant fabrication to get it to fit (the DOHC V6 is much wider than any engine the 67 came with)
You would need new radiator
You would need a new transmission
You would have to do some fabrication to get the transmission to fit
You would need a new driveshaft
You would need a new steering rack (The 3.7L uses electric power steering)
You would need new accessories (alternator, A/C if you have it, etc.)
There will be issues with the engine's ECU as it'll expect input from sensors that that 67 doesn't have
You'll need a new fuel pump
You'll need a new fuel system ( the 3.7L uses a returnless style system)
You'll need a new exhaust
and I'm sure there's alot more stuff that I overlooked
In short, you're going to end up spending much more than the car is worth trying to get this work. Fuel mileage shouldn't even be a factor, I mean you're already spending around $15k as is, at that point an extra 3 or 4 MPG isn't going to make much a difference, compared to the money you've already spent. No offense intended, but I don't think you realize the difficulty and expense of what you are proposing.