The 6 cyl Mustangs used 4 lug wheels, smaller brakes, lighter springs, and lighter suspension components compared to the V8 cars. Therefore I would upgrade those items before adding the additional weight and power of a 351.
That said the 351W will bolt in with small changes to the exhaust(Hedman makes swap headers) and a drop base air filter to clear the hood, even with a stock height intake. The transmission will also need upgrading to a V8 compatible trans.
The 351C will also fit but it is much tighter and requires some special pieces to install, namely headers, motor mounts and will likely need more clearance with the shock towers.
The 351M is not even an option as far as I am concerned.JMO
That said the 351W will bolt in with small changes to the exhaust(Hedman makes swap headers) and a drop base air filter to clear the hood, even with a stock height intake. The transmission will also need upgrading to a V8 compatible trans.
The 351C will also fit but it is much tighter and requires some special pieces to install, namely headers, motor mounts and will likely need more clearance with the shock towers.
The 351M is not even an option as far as I am concerned.JMO
