With no doubt this would be the number one cause of tick after cam install, now if it wasn't ticking prior and it sounds like that is the case, then in theory at least this is fixable. There is a large % of hemi's that tick before and after cam install. Look up lubrication strategies in my sig to help lubricate the cam with ep additives to better protect it long term. If this is the case, you will need new rods because if it ticks it is likely bent.
from link
With the rods in place start with the exhaust rocker arm, it’s the easy one. A trick I have is to place a dollop of assembly lube on the end of the push rod to hold it against the rocker arm. Place the rail onto the towers and tuck the pushrod into the cup of the rocker arm. Luckily this side stays quite easily. Begin tightening down the rocker arm starting in the center until the bolt touches the retainer then the middle then the outside. You’ll notice one side of the rocker arm will most likely close right flat and the other will have resistance, this is normal. Just tighten down the rocker arm keeping in mind that you want to gradually get the whole arm down as in line as possible so don’t crank the easiest one down tight then go to the other end and bring it all the way tight; this is how you snap rocker arms when they start working under load.
I will note that you should make sure the flat part of the rocker arm is sitting directly on the top of the valve inside the spring while everything’s being set into place.
The intake arms are a bit more of a pain but if you take your time it takes no real hassle. The problem with these is the rocker arms don’t hold the rod in place all the time so they continuously drop out. If you have a helping set of hands to hold the rods in place great, but I’ve never had them so I just have to keep popping the rods back into the rocker arm cups. You follow the same procedure to get the rocker arms into place, just keep checking the rod hasn’t fallen out of the cup while the arm is being tightened into place.
I have an older set of rocker arms which is why mine have an "I" stamped into the intake arms but you can't get them backwards as they will not line up with the valves if you put the intake rocker onto the exhaust side.
With the rocker arms in place, loosen the bolts slightly and then torque everything into place. Loosen them just a bit so you get an even torque all the way across and to ensure you didn’t over tighten anything while you were loading the rocker arm.
