What would be the symptoms of a timing chain being one tooth off? This is on a 360.

loss of power. hard to start. runs like junk

put your marks on TDC & see where the rotor is (whether #1 or #6) it'll be way off from the underside of the dist cap terminal. More details, what happened.

I think if you pull the fuel pump you can feel for the slop in the chain. Does this maybe have the phenolic top sprocket? If steel, there's very little chance that it's slipped.

Quickest way, is that IF you know where the timing is supposed to be, and it's way off, it's slipped.

Take a wrench and rotate the engine cw/ ccw against the chain "slop." If it's 10* movement or more, I'd be suspecting slippage.

Is this a new installed timing set, or what are we working on? In all the years of working on this stuff about the only time I have seen a timing chain off a tooth is if it were installed that way. It can happen but the vast majority of the time if a chain goes south it is is because it is running on the plastic sprocket and the sprocket teeth go away and the chain literally spins on the sprocket. When this happens you will have not so cute little eye brows on the pistons very likely along with some bent valves.

Pull the distributor cap.

Rotate the crankshaft back & forth with a socket wrench while watching the rotor.

If the timing chain is worn, you will be able to move the crank a few degrees without seeing the rotor move.

If they do not move together, replace the chain & gears.

just checked, the timing chain (new chain) is dead on. Harmonic balancer is good (didn't slip). Back fires out the carb at rapid throttle and has steady 9" of vacuum with timing set at 35 degrees at 3000. Now if we set the timing to 45 degree the vacuum is at steady 17" no popping out of the carb and the engine seems to run fine except for a miss between 1800 to 2300 RPM.Rotor points to #1 wire. Compression test is normal.

Sounds like you may need to add initial timing and limit the extent of the full advance. Or is the advance locked out already?

Are you sure the harmonic balancer hasn't slipped on its rubber ring, giving you incorrect timing with the timing light?

Make sure that the distributor is calibrated to be fully advanced at the RPM that you are checking the total at.

check your plug wires, I had one with a cut in the insulation and it would short out intermittentlly. it idled fine but under power you could feel the miss., almost like a timing chain studder.

Gary.

This may sound crazy but I worked as a tech for dodge dealers thru the 70's and they had a problem with the 360's, when if the motor backfired it could pop the seat off the EGR valve .Dont know if your car still has one on it but it makes that type of noise. EZ to ck...just take off the valve and look at it....the little plunger should be seated in the valve body... Just a thought

Did this happen after the chain set was replaced? I believe there was a run of spockets (sorry don't know which manufacter) that were mis-marked out of the box. It maybe worth it to degree your cam.

when setting the timing did the timing marks stay steady or were they erratic?maybe the oil pump/distributor drive gear is worn.

Not tryin to be a smart a$$ but double check your plug wires.
I kno it sounds too easy but... its happened to me mor than once, 6 & 8 crossed will produce similar symptoms
Let us kno what ya find,