Reply to "Boring 351C"

This is about saving a block for street use. If you're trying for 500+ bhp or high rpms, this post is irrelevant. One should understand that most bore wear is at the extreme top of the cylinder. That area gets no oil, is above the ring contact area and does NOT need to be flawless. All it needs is enough of the wear-step tapered so you don't break ring lands when removing/replacing the pistons. That's why I typically HONE cylinders that are not badly damaged, rather than boring. Even minor pits left after honing are not cause for scrapping (or boring) a block.

Forged 2618-alloy pistons expand when hot & running, so they can accommodate up to about 0.005" of oversize: e.g- a 4.005" cylinder can use a 4.000" 2618-forged piston but NOT a cast/hypereutectic. Such mismatches will rattle on startup but quiet down within seconds. Forged alloy 4032 has quite a bit of silicon in it which makes those pistons not expand as much with heat, and are more brittle. They won't tolerate 0.005" oversize bores without cracking.

As far as sleeving, one cylinder on each bank will work fine. More than that is iffy for high horsepower. The weak spot in a stock block is at the bottom of the cylinders where the bores get close to the main bearing saddles. That area is weakened even more in the huge overboring needed to add sleeves. Good luck.