The weak link in the 440 are the 3/8" rod bolts. They are the same as a 318 rod bolt (3/8"). If you rev the 440 over 6,200 RPMs, those heavy pistons really start to stress those 3/8" bolts. They will stretch, opening the rod bearing clearances and let the bearings spin over top each other (piggy back). Keep your RPMs below 6,200 and it will last a long time. Keep spinning it to 6,500 or over, you'll be buying parts real soon.