Hi! Depends where you look for valve covers. There's places that still carry them in limited quantities and they're OEM. Mine is a V6 and I replaced mine because the spark plug gaskets are integrated into the valve cover while the cover gasket is separate. When I look at the V8 version, the gasket is a single gasket that seals off the valve cover and the spark plug holes.
I'm not certain you need to replace your covers but I can't say 100% certain because while they are the same material as the V6 version, they have a different shape/design and with that could potentially mean they act and age differently. On the flip side, they might be designed to never require replacement which is what I speculate is the case seeing as they're discontinued. From what I've seen with Japanese brands, they usually discontinue parts that don't ever need replacing from normal wear and tear or there's just so very few of them in the world that there's no need to keep making parts.
The covers are made form fiberglass reinforced plastic for high-heat applications. The only place gaskets get sticky is near any corner because that's where silicone is applied. When your mechanic removes the existing ones, they'll need to take their time with removing them. When your mechanic puts back the covers whether old or new, they'll need to apply a bit of silicone in every corner there to ensure there's no leaks.
Here's some part numbers I've come across but as always, have these vetted by the mechanic/dealer as Infiniti tends to have variants based on production date.
GASKETS
Passenger side gasket: 13270-1CA0A
Driver side gasket: 13270-1CA0B
For covers, when I look up the part numbers, there's like 3 sets that potentially correspond to your year so what I would do is find out from the dealer using the VIN and seeing what the part numbers truly are.
But from what I can see, these are the part numbers that are coming up:
COVERS
Passenger side: 13264-1CA2A
Driver side: 13264-1CA2B
I was able to find them on this site which I've used for years and many of us here have as well:
Passenger Cover
Driver Cover
I always go for non-express as it only saves you a day at best and the extra cost is unnecessary. Takes about a week usually for DHL and FedEx. There's EMS which is about 2 weeks give or take. If you're not in a rush, might make more sense. But if you're going to order the covers, grab the gaskets as well and possibly anything else you'd need.
Just a side thought, if you're getting your covers replaced, see if you need spark plugs or the starter replaced. Good time to jump on those as the starter literally sits between the two covers. When I replaced my valve covers, I replaced my knock sensors and rear coolant sensor because it was just easier and I was at that mileage where these things are just ticking away at failing. But that's just me.
Hope this helps!
