another ticking question - 380 SE

85 380 SE 188,000 miles, new chain, etc., at
133,000.

well, we've developed a top-end ticking noise on the
left side and i'm wondering if anyone can give me some
insight.

it is constant in conjunction with motor speed, just started about a week ago when the temperature dropped; haven't taken the valve cover off yet (waiting for the weekend and hopefully 50 degree weather).

when i started hunting it down, it sounded more in the middle of the left valve cover area, so i'm thinking (hoping) away from the chain and guides. on further listening with my shadetree stethoscope (large, long screwdriver affixed to the large right ear) it sounds like it's coming from the area around the injector valves and beyond the air distributor hose. of course i know sound transfer can be tricky and/or questionable, but anybody want to take a shot in the dark?

i'm in the light mechanical ability range but have strong supporting cast (in other words, they tell and i do what i can) and i will pull the valve cover this weekend. i know one cam lobe near the fire wall is pretty banged up, but this sounds closer to the fuel
distributor and air regulator to me. do the injector valves tick like that when going south?

thanks in advance.