The stethoscope is very sensitive. This can be good and bad. Keep this in mind. Sometimes using the less sensitive 'big screwdriver to the ear' method works better.

Diagnosing sounds on the internet is very difficult. How the OP (you) uses words means much. You used the word "ticking". A high pressure air leak or high voltage spark leak both will make a ticking noise (and should affect running). See the problem? Words like 'tick', 'click', clank' etc do not capture a lot. It is simpler with things that have gears inside when the words 'clunk', grind' and 'gnash' emerge.

It could be a sticky valve, a rocker hitting the inside of the cover, slop in the rocker blocks, timing chain slapping the bearing carrier, and on and on and on. Your stethoscope should help isolate if the noise is truly on the right only and more towards the rocker cover or cylinder base.

It is worth noting the cadence of the noise. The cam runs at half crank speed so lifter and valve train noises are slower in cadence than big end bearing/crank/piston/etc. noises. Spark plug noises run at crank speed.

Note whether the nose is present immediately on start-up or emerges as the engine warms up.

The rocker blocks are high on the 'usual suspects' list. So do a valve setting, look for a rocker hitting the inside of the covers, fit fresh rocker cover gaskets.

Thanks for the response Arni,
I have done two valve settings in the last 2 months, an initial one around a month ago and one last week after a long trip. The first time I set the endplay and it remained tight. I also verified that it was not hitting the inside of the cover and I have already fitted fresh valve cover gaskets. Based on the cadence, it does sound like a valvetrain noise and it does seem to be coming only from the right side. Could the noise be coming from the pushrods or the lifters or something else in the valvetrain that could be causing the noise and how can I check for that?

Small exhaust leaks sound amazingly like "ticking". Check around the ex pipe -to-head union and the ex cross-over tube.

Time for Arni to have his nightly chocolate vodka cream so typing and ideas may get more ragged. I beg forbearance.

Lifter noise will come from the cylinder base, rocker noise from the top.

I would reset valves on right. per procedure. Always spin push rods between the fingers before setting valves. They should feel smooth. The right is a bit tricky as it is more difficult to look through the timing hole. It is critical to turn the engine forward when coming up on OT. If you overshoot back up a quarter rev and come at it again. This takes up slack in the timing chain and gives an accurate setting. Use go/no-go feeler gauges. Unless you use the plain ones a lot the go/no-go will be more accurate. As a rule the last thing you monkeyed with is suspect for any problem so go back over your service log (hint: valves)

A leaky head gasket is a high pressure air leak but runs at crank speed. (Wobbley check me on that). Anyway the Dx is a leak down test which wouldn't hurt anyway.

Torque the head + cylinder studs----carefully. Do not strip a stud out of the block = hatin' life.

Leaving the cylinder bolted up pull each rocker assembly in turn as well as the push rod. A worn spot on the pushrod from the head gasket is normal, but should just be a bit shiny, not excessive= ridges. examine ends for smooth and shiny. Examine rocker face for pitting and bearings/bushings for intactness and smoothness..

Exhaust leaks run at crank speed but the nuts need service anyway so wouldn't hurt to check. Look for carbon streaking.