Ticking Sound From Right Side of 340

1970 340 Six Pack has a ticking noise on the passenger side of the engine. Louder cold quiets down as it heats up. Sounds exhaust related but not completely sure. How should I diagnose and fix?

Get a cheap mechanics stethoscope at the parts store and use it to listen for and trace the noise.

Yes this, or just use a piece of fuel line hose. Hold one end up to your ear and the other end down around the exhaust manifold and move it around.

Beside hearing a exhaust leak clearly I have also felt warm air in my ear when I found a exhaust leak with a plain piece of hose or plastic tubing. Any type of tube will work and works really well.

And I did buy a cheap mechanic stethoscope but didn't like it, was not clear enough for me and went back to regular old piece of tubing that seems to work better for me.

In my experience, louder when cold means loose rod

Exhaust, passenger side, it's probably coming from the heat riser.

Major difference between a tick and a knock.

if your 340 has some miles on it I have seen a lot of them with a lifter or two gone bad. try a bottle of marvel mystery oil. if noise goes away, probably a bad lifter. of course the ultimate fix is new set of lifters.

exhaust/lifter/pin (in order of likelyhood/severity)

Years back when I had my Valiant, I had the same issue with it's 318. Passenger side head ticked loud cold, fairly quiet when warm. Mom said the car ticked since they drove it out of the dealership.

I didn't spend any time on the 318 heads, but swapped on a set of 360 small-valve heads and a 4 bbl intake. The ticking went away, so I can only assume it had something to do with the head.

Currently, the 304 in my AMC Hornet is doing the same thing. Passenger side ticks. All the lifters seem good so I can only assume it's the same issue as with the Valiant. Either a poorly lapped valve, or maybe an exhaust valve rotator has stuck and is wearing a valve prematurely.

I had hoped it was just an exhaust leak, but I changed all the gaskets (and don't run a heat riser) and that didn't change anything.

I'm pretty sure it's the heat riser. That's where the sound is coming from and it has a ton of in/out play. What are my options to fix? I don't care whether it works or not but would like to keep the outer parts looking correct if that makes any sense.

GOING WAY BACK!!! on the 340's
IF the motor still has the factory steel shim head gaskets, they were known to blow out the bottom of the cylinder between the block and head. Why?? because there were only four bolts per cylinder and the head bolts / gasket lost torque over time which resulted in a cylinder leak that sounded a lot like and exhaust leak. This issue typically appeared on the center cylinders around 80 to 120K miles. if the motor has been opened up over the years it is probably not the cause of the noise. But wanted to throw it out there.
Also wanted to say that if you wire the heat riser open
(assuming it might be partially closed) it would eliminate the back pressure forcing the noise to become prominent. unless of course the exhaust is restricted elsewhere which based on the description is doubtful

It's been rebuilt. The heat riser moves freely. Too freely lots of in and out play. It flops back and forth opening and closing in and out while running.

The heat riser is supposed to have a thermal spring on it that closes the butterfly when cold and opens it when warm. try wiring it open and see if your noise goes away

Yes the clanking part of the sound goes away and much quieter but I can feel/hear exhaust coming out around the shaft of the heat riser. Much much better though

Part of the kit for the rebuild is a couple of metal cups that act as seals.

Me , I remove the heat riser completely , no need for it on a car that rarely sees temps below 40 ...

I have a manifold I'm going to make it LOOK like it has a working heat riser