Early Ford Mustang Engine Conversions V8 from Inline 6

Upgrading a Mustang is relatively easy. Select the appropriate engine mounts, radiator and change the fuel lines if swapping from a L6 to a V8.

Motor Mounts

Early 65 mustangs (built prior to 11/01/65) will require a V8 engine support bracket if you don't already have it. This mount combination has a stud on it. Part #'s XH50 and FJ5151 will get you a frame bracket & engine mount combination.

Mustangs from 65 (after 11/65) on up will have the bracket you need welded onto the car, regardless of what engine was installed. The only thing required is to obtain the appropriate engine mounts for the engine in question.

Windsor & Cleveland engines - use the same mounts, and since the engine was available from 1965 on up, you simply need to obtain the correct V8 engine mount which is part # XH51.

FE - Originally available in the Mustang beginning in 1967 - to install a 390 or 428FE in a 1967 to 1971 Mustang use part # XH54.

"Convertible mounts" - will lower the engine 1/2". These can be used on a coupe to lower the engine.

Recommended modifications:

Radiator - With increased power comes the requirement to get rid of the extra heat. We offer a wide variety of radiators. To select the appropriate radiator, simply select the YEAR and ENGINE CID that applies to the car in question. The core support on your car will support whatever radiator was originally offered.

Choosing a "heavy duty" or "A/C" radiator will get you the largest stock radiator available.

Radiator interchange is 65 to 66, and 1967 to 1970.
The waterpump outlet changes in 1970 on the windsor/cleveland so you need to match your radiator with your waterpump (or vice-versa). For example, if you have a 1975 351W engine and you're putting it into a 1968 Mustang - buy the "1970 radiator". A 1969 radiator has both outlets on the passenger side. A 1970 radiator has the upper outlet on the passenger side, and the lower outlet on the drivers side. The FE engine will position the lower hose on the drivers side.


Other considerations:

Fuel lines - the fuel lines differ from a 6-cylinder mustang to a V8 mustang. See our catalog to obtain the appropriate fuel lines to support the engine style & year of vehicle.

The sending unit in the tank is the same - regardless of original engine option.

Brakes - the 6-cylinder brake system uses different spindles and a smaller drum than a V8 car. It also has a different wheel bolt pattern (4 lug - vs. the V8's 5 lug).

Exhaust - Select the appropriate exhaust, either stock exhaust manifolds or headers. Select items that match both the engine style and chassis year. Keep in mind, the C6 automatic transmission is physically larger than a C4 and will cause header fitment issues. If installing a 351W or 351C in a 1965 or 1966 Mustang you will need "engine swap" headers.

Transmission - Select the appropriate trans based on bellhousing. The C4 is capable of handling most engine packages in a mustang, so that's the preferable transmission.

Rear End - Several rearends were used on the Mustang, typically an 8" - sometimes a 9". The 8" rear is adaquate in most cases. If converting from a L6 to a V8 - you'll want to use V8 axle shafts.