[496fe]

If I'm not mistaken, the 428 service block had thicker cylinder walls. I think that's why he makes it clear that these are SERVICE blocks. A number of stroker kits give the FE a 4.250 stroke. 4.250 X 4.250 = 482 CID. The new Genesis, Pond, Shelby etc can be bored out to 4.310" safely. My 496 is 4.250 X 4.310"