Beautiful engine bay. I am running Castrol 10W-30 in mine with a Zinc additive for the hydraulic flat tappet cam. I had lifter tick on my 340 but that was a different issue that was rebuild assembly error from prior owners. (Too short pushrods). I have currently redone that and going to switch from a shorty filter to a larger oil filter that is remote mount (headers).
You may just be experiencing the lifters pumping back up after sitting all winter, which could take a few minutes for sure. I wouldn’t get too excited as long as you have good oil pressure and the tick goes away after it warms up.
I hope you have a battery hold down not pictured because that is a beautiful engine bay, hate to see the battery get loose in there.
