Maximum overbore for FE engines
| Block | Stock Bore (Nominal) | Oversize Bore (maximum) | |
| 332-352 | 4.00" Dia. | (0.060") 4.060" Dia. | |
| 390-410 | 4.05" Dia. | (0.060") 4.110" Dia. | |
| 406-428 | 4.13" Di-'. | (0.060") 4.190" Dia. | |
| 427 | 4.23" Dia. | (0.030") 4.260" Dia. |
The Cubic inch Displacement chart shows regular production volumes in white, The numbers in gray indicate other possible
displacements by "stroking" with stock cranks. Many other displacements are possible using non-stock crankshafts, or by
boring blocks oversize. However, if you go this route be sure and stay within the overbore specifications for FE engines
Cubic Inch Displacement Chart
| 3.30" 332 Crank |
3.50" 352,361T Crank |
3.78" 390, 406, 427 391T Crank |
3.98" 410,428 Crank |
|
| 4.00" (332-352 Block | 332 | 352 | 380 * SI-3 | 400 * SI-3 |
| 4.05" (390-410 Block | 340 * SI-1 | 361 * SI-1 | 390 | 410 |
| 4.13" (406-428 Block | 354 * SI-2 | 375 * SI-2 | 406 (405) | 428 (427) |
| 4.23" (427 Block | 371 * SI-2 | 393 * SI-2 | 427 (425) | 447 * SI-4 |
Special Instructions
*SI-1 340 and 361 CID
Use special non-Ford pistons to maintain correct deck height clearance. Stock 390 Police Interceptor type rods with nut and bolt to retain caps okay for street and medium performance applications. For all-out high performance use 428 SC J/427 rods With cap screw to retain caps are recommended. However, 0.010" must be taken off each side of journal end for clearance in 4.05" bore. Slightly narrower special non-Ford rods can also be used.
*SI-2 354, 371,375, and 393 CID
Use special non-Ford pistons to maintain correct deck height clearance. Use 390 P.I. type rods for medium performance ap\-plications, or 428 SC J/427 rods for high performance use.
*SI-3 380 and 400 CID
Use special non-Ford pistons to maintain correct deck height clearance. Use 390 P.I. type rods for medium performance ap\-plications. 428 SCJ/427 rods too wide for 4.00" bore. Special non-Ford rods required for high performance use.
*SI-4 447 CID
Use special non-Ford piston with pin hole that is 0.100" nearer top than standard piston. Note: The 1968 hydraulic cam 427 engine used a flat top with knorbs piston that can be made to fit by taking 0.100" off the top. However, the resulting piston wall thickness is below standard for all-out high performance use.