W124 300E engine parts needed
 

I have a W124 300E gas MBenz, which engine(103983 6cyl) is with some noise and spartk plugs must be clear frequently. I´m thinking to rebuilt this engine and I like to know which parts and sizes should I have to buy beyond the piston ring set, main bearing set, block lower gasket set, cylinder head gasket set...
A am in Brazil and I have to import this spare parts
Thanks

Provide some additional details about your 1991 300E ... mileage, maintenance history, how many owners. The lower half of the engine should be good for 250,000 to 300,000 miles ... so it's unlikely that you need crankshaft bearings. When were the ignition wires, distributor cap and rotor replaced last? A new coil may improve engine performance. I'd try the inexpensive maintenance items before doing a major engine rebuild.