B grade pistons in a 4.6

[gimebakmybulits]

Are B grade pistons a sure sign of a rebuild (4.6) or could new production engines have gotten them too? The Rave seems to indicate service rebuild.
NOTE: Pistons fitted on production are
graded ?A? or ?B,? the grade letter is
stamped on the piston crown.
Production piston diameter:
Grade A = 93.970 to 93.985 mm (3.700 to 3.7002 in)
Grade B = 93.986 to 94.00 mm (3.7003 to 3.701 in)
Grade B pistons are supplied as service
replacements. Worn cylinder liners fitted with grade
?A? pistons may be honed to accept grade ?B?
pistons provided that specified cylinder bore and
ovality limits are maintained.

 

[special ed]

I only remember seeing B pistons in a confirmed warranty replacement motor. I dont think it was a factory Reman but a new replacement engine. If you are dealing with a 03 or an early 04 disco engine a lot of them did not make it past 30,000 miles or even the 1st oil change due to cracked oil pump drive gears.

 

[pdogg]

I've owned my 2002 4.0 D2 since 17k miles.. recent rebuild shows all B-grade pistons.. not sure why, since I don't know the car's history.

my block cracked and I had it rebuilt with D&D