Ford Piston 4.2 STD. 3 x Ford Piston 4.2 STD D6NN6108L. Don't Settle for Second Best. Please advise which size piston & rings and conn rod bearings you require when ordering. Ford 3000 tractor 175 cid diesel engine 4.2 overhaul kit many of our suppliers are the same suppliers that sell to original equipment manufacturers.