1968 Mustang Engine Information – 427 cubic inch V-8 (7.0 FE Hipo V8)
This engine was offered for one year only in the Mustang. It was very expensive to make and offered less value to the customer than the 428 engine. It was dropped after one year and the 428 became the engine of choice for the performance group unless you could afford the “Big Boss”.
Engine Basics
| Year | 1968 |
| bbl | 4 |
| Cylinders | 8 |
| Power (hp) | 390 hp @ 5,600 RPM |
| Torque (lb/ft) | 460 hp @ 3,200 RPM |
| Compression | 10.9:1 |
| Displacement | 427 cu / 7.0 liters |
| Bore x Stroke | 4.236 x 3781 |
Engine Torque Specifications
All torque specifications provided in this table are those recommended by FORD. If you use special bolts, follow the torque specifications provided by the manufacturer. I recommend that you use the 3 step torque technique where you torque down the bolts in three equal steps. Once you have reached the maximum recommended torque setting, go around one more time. Do not torque in a circular pattern. Always torque cross to cross.
| Head bolts | 100-110 |
| Crank cap bolts | 53-58 |
| Rod end caps | 95-105 |
| Intake bolts | 32-35 |
| Exhaust manifold bolts | 18-24 |
| Harmonic damper | 70-90 |
| A/C Compressor mounts | |
| Engine fan | |
| Motor mounts to engine | |
| Bellhousing bolts | 25 |
| Trans to bellhousing | |
| Flywheel to Crankshaft | 75-85 |
| Oil pan bolts | 12 |
| Valve cover bolts | 10 |
| Carburetor mount bolts | 10 |
| Oil pump | 15 |
| Spark plugs | |
| Trans. inspection plate | |
| Water pump bolts | 20 |
| Clutch pressure plate | 35 |
| Water pump | |
| Upper cam gear | 40 |
| Rocker arms | 45 |
| Main cap cross bolts | 40 |
Crankshaft Bearing Journal Specifications
Main Bearing Journal (inches)
| Journal Diameter | 2.7484 – 2.7492 |
| Oil Clearance | 0.0010 – 0.0031 |
| Shaft end play | 0.004 – 0.010 |
| Thrust on number | 3 |
Connecting Rod Journals
| Journal Diameter | 2.4380 – 2.4388 |
| Oil Clearance | 0.013 – 0.0032 |
| Side clearance | 0.010 – 0.020 |
Piston Ring Specifications
Comp Ring Width
| Top | 0.0774 – 0.0781 |
| Bottom | 0.0930 – 0.0940 |
Ring side clearance
| Top | 0.002 – 0.004 |
| Bottom | 0.002 – 0.004 |
| Oil ring | Snug |
Ring gap width
| Top | 0.010 – 0.031 |
| Bottom | 0.010 – 0.020 |
| Oil Ring | 0.015 – 0.066 |
Piston Specifications
| Code Red | 3.9984 – 3.3990 | 3.9978 -3.9984 (HP) |
| Code Blue | 3.9996 – 4.0002 | 3.9990 – 3.9996 (HP) |
| 0.003 Oversize | 4.0008 – 4.0014 | 4.0002 – 4.0008 (HP) |
| Piston to Cyl. Bore clearance | 0.0018 – 0.0026 | 0.003 – 0.0038 (HP) |
| Piston Pin Bore Dia. | 0.9123 – 0.9126 | 0.9123 – 0.9126 (HP) |
Valve Specifications
| Year | 1968 |
| Seat angle | Intake 30, Exhaust 45 |
| Face angle | Intake 29, Exhaust 44 |
| Valve spring pressure lbs/inches | 268 @ 1.31 |
| Valve spring installed height (in) | 1 13/16 |
| Stem guide clearance (in) – Intake | 0.0010 – 0.0024 |
| Stem guide clearance (in) – Exhaust | 0.0020 – 0.0034 |
| Stem Diameter (in) – Intake | 0.3715 |
| Stem Diameter (in) – Exhaust | 0.3705 |
