I have a 89 460 with 71,ooo miles on it.

It has a severe knock & ping problem under load.
I have added:
new injectors, control module, pick up coil, fuel pressure regulator, map sensor, tp switch, fuel filter, senders etc.....

However nothing seems to work. There was alot of carbon on the Throttle Body & I was recently told that there may be carbon build up on the valves so I ran "Top Clean Engine Cleaner" 6 cans of it through ...still knocks.

Truck runs rich, backfires through the pipe but timing is correct.

I was told to do a valve job, also was told it may be premature wear on the distributor gear & camshaft gear. Maybe it jumped time?

Does anyone have any idea what it may be?
I'm on the verge of ripping this engine out.

 

Not familiar with the 460 but I have had a wicked ping issue recently. Turned out it was 2 plug wires ,firing one after another in firing order(#7&8), that were too close together. The voltage would go sailing down one wire, jump to the other, and ping the wrong cylinder. Especially under load. You could try higher octang if you cant figure it out.
How are your vacuum lines?
Last plug change?
Last cap/rotor change?

 

how much for your 460?