Hey I have a 93 460 5 speed. I have new plugs wires cap rotor, distributor, heads plained, valve job and new exhaust valves. Also have new timing chain and gears. When the engines under load it pings badly and has a miss fire. No vacuum leaks. Running 93 octane. Timing is at 12 degrees. I have headers with the egr valve blocked off. New intake and head gaskets. I'm probly forgetting some info so just ask. Thanks

 

Try backing off the timing

 

I had it at 10 then changed it to 12 then 14 and back to 12. Made no difference in pinging. Going the wrong way maybe? Switching it from 10 to 12 did get rid of the what felt like a thump coming from the exhaust(small backfire maybe?)

 

Play with the timing. Also, try a lower octane gasoline. It should be meant to run right on 87.

Also, you mentioned that the EGR was blocked off... Is there also a pump? If so, it may need to be disconnected. I know someone with an earlier 460 that would get bad misses and backfires after headers and dual exhaust and he found that it was due to the EGR pump still being connected even though he wasn't using the EGR system.

 

No I took all the emission tubes and pump off. I'll check the engine light tomorrow. I took the bulb out for the previous engine egr code(351w). Also the truck has a new o2 sensor

 

My guess is removing smog equipment on these computer vehicles is a mistake in my experience. All the air pump does is cool exhaust temps & that could be part or all of your ping. On my 86 F250 4x4 460/C6 a carbed vehicle I removed the smog pump to find a ping under heavy load that nothing got rid of it.
Craig

 

Maybe it is not a ping. Maybe you have piston slap.

 

^^I don't wanna think about that haha. But if timing makes no difference in the pinging it makes sense, especially with my luck

 

Just removed the timing cover. Marks are perfectly pointing at each other with piston 1 tdc

 

Checked it again twice. Timing is fine