Where do I look for the numbers. I have a 67 vert with a 350. I pulled the valve cover on the driver's side and found 85 in the middle of the back rockers close to the firewall. There is a 14 up towards the carb. Heading towards the front of the engine I found what looks like seven 8's, then in the middle I found 4GM and towards the front I found recro en mexico. And to add to the fun the PO was running motorcraft arf 4 spark plugs. I looked at the front of the engine on the ends of the heads but I don't see any numbers. I am not looking in the right areas? Thanks for any advice. This motor is some type of replacement 350 from the late 70's with a standard 68 intake and a qjet from 69. Anybody know about the ARF 4 spark plugs? They are shortys.