Pieces of steel in cylinder??

brass freeze plugs
polish is good if that works
.060 is fine
or turn the rod throws down to chevy size (or Honda)
or cut the mains to 318 size if a 360 crank sell it with the dampner
what NM just said
340 cam is a step 50 years back in time but it's cheap
but do not advance another 4 degrees- kills your power stroke and mileage
new timing chain