truck noise, please help!

Hope anyone can help with this. I read all the posts dealing with pinging and my question remains.
86 2wd 4spd 22r 270K, did oil change, carb clean, and air filter two days ago, decided for some dumb reason to upgrade to plus gas. Imediately began to ping. Dull, metallic clatter, increases with accelleration, but only starts at mid-revs. Sounds low on motor, driver's side. Never did this before. Please help, I just decided to redo the body and now this, can't afford to overhaul.

is the plus gas higher octane?? It might be preignition, if you don't like it, drain the gas, otherwqise your going to have to burn it all out, I could be wrong, but you might be able to overcorrect it by changing the timing until the gas gone, good luck.

xtoyotacorex, sounds like a valid point. Did a long drive yesterday, after checking with a fellow from the shop who said the sound wasn't anything dangerous, and refilled with regular gas. That sound has stopped. Wondering also, could the carbon that was cleaned out of the engine, when I did the carb, have somehow lubricated either the timing chain or some oher part that could have been causing the noise? Thanks for responding, I do appreciate it:)

no, your carb clean wont touch the timing chaing, the only fluid that can touch the chain is your engine oil, unless you have a blown head gasket or something. If your chain on your toyota goes out you will know it.(it'll sound like a chain rotating loosly when you drive, it's quite loud and noticable, and consistent, mine is actually going out now) Lubricating something in your engine probobly wont make a noise. I'm sure it was the gas, don't use anything but the recomended octane gas for your yoda, what i meant to say was post ignition, your higher octane burns slower so your gas wasn't detonating at the right time, thus causing a noise.

Ok, a follow up: about 70K ago this noise first happened, it too was right after a thorough carb clean. I freaked and bought some Dura Lube (I know the crap in the cans is just crap) ,a good long drive on the freeway after the DL and the noise had disappeared. Didn't show up again till now (funny, after a carb clean) So I did the same thing, bought the DL, poured it in and went for a highway drive. Noise is gone. WTF? I talked with the guy from the shop up the street (didn't tell him about the DL), and he said it could possibly be the fuel pump, or water pump wearing out. Any thoughts!
By the way, it seems to have nothing to do with the gas situation, thanks for the suggestion though:)