Why can't auto parts stores find my engine?

I have a 1996 Mitsubishi Spyder. Gst I bought off the used car lot. I took it to advance auto parts and autozone. Both places I went for a valve cover and they didn't fit. I thought maybe my engine was swapped. Thru some research I found out my engine is a 4g64 dohc. It dosent help because I can't have them search by engine. I tried every kind of Mitsubishi and none of the parts match. I googled search a 4g64 dohc and there's my engine in a Spyder. Where can I go for parts?Why can't auto parts stores find my engine?
GST huh?? It's a 4g63 Dohc Turbo.
If it's a GS, it's a 4g64 SINGLE overhead cam.
A 4g64 DOHC was found in the RARE 1994 Galant GS. ONLY. I've seen three in 20 years.
Go to a junkyard. Before you do that look up your engine on google or something and find out what cars had that engine and them look for those cars at a junkyard. You could just also search for the car that the engine if from's valve cover on google.Why can't auto parts stores find my engine?
Have you researched down a year, up a year in production? Sometimes small things change between years. BTW I believe the Eagle talon had the same engine that year?
Mitsubishi !Why can't auto parts stores find my engine?
try you Mitsubishi dealer.