Happy Holidays!!

Does anyone know the longevity of the ignition coil, water pump, and spark plug wires on a 88 740 gle (non-turbo)? One of my 88 740 wagons is fast approaching 368,000 miles and i wanted to know how much life is usually expected from each of this items. I will be replacing my timing belt in another 9,000 miles. My ignition coil is from Bosch. Also what is the very best timing belt, ignition coil, and water pump of the highest quality that one could buy besides the Volvo brand? The engine itself is running fine for such high mileage (well pampered), my spark plugs depict a normal running engine. Also what would the 3 seals, and oil pump bolt costs me when i replace my timing belt? I use nothing but quality parts, but do you guys know of anything else that might benefit these incredible machines of mine? Any and all experiences and knowledge would be greatly appreciated!! Oh one other question, should i decide to have the dealer install a new timing belt, oil pump bolt, water pump, and 3 seals, what kind of reasonable costs might i expect to pay? I reside in the northeast. I commute 1,200-1,400 miles each week, in addition to averaging 75-85 MPH (98% hwy miles)and 25-30 MPG without even a hiccup! Next stop 400,000 miles!!! Please share your thoughts.

Best Regards!

88 740GLE Wagon (non-turbo)AW-70 A.T. 367,500 MILES/88 740GLE Wagon 173,000 miles (non-turbo) AW-70 A.T. 96 Nissan Maxima SE 175,000 MILES. Premium fuels, polishes, waxes, leather conditioners etc (Always). Full Amsoil lubrication/filtration. Shell Rotella ELC 50/50 DILUTION, and NGK V-POWER Spark plugs/Bougicord plug wires. Premium parts in addition to being proactive and not reactive to any issues regarding either vehicle.