1972 super cheyenne knocking 454
 

i was told it is a 454 but could be bb 400 anyways the timing is at of whack #1 at #8 cynd. but any how top end was rebuilt so the say if the timing is really out of whack and if the lifters are to tight could this cause a knock and heavy black/gray smoke any thoughs thanks Mark,

Re: 1972 super cheyenne knocking 454
 

You're gonna need a little more info than that - get the plug wires and timing straightened out first, then you'll have a better idea -

Re: 1972 super cheyenne knocking 454
 

Timing out, can cause a nasty spark knock. Combined with a poor performing carburetor, the engine could be lean or rich. Rich mixtures will cause a sooty exhaust, and a noxious exhaust that will make your eyes water and give you a head ache in short time.

Tight valves in my experience can cause back fires out the carb, and or a rough idle.

Engine cubes don't matter if the ignition timing is incorrect, and the intake/exhaust valves are miss adjusted. No matter what size, it's gonna run badly.

Like noted above, get all that tuned and adjusted correctly asap.