Pull the valve cover off and look at the rocker arm assemblies, if its mechanical lifters I'd highly suggest converting it to HLAs. I swapped mine out for HLAs shortly after I got the car because it's much less headache than trying to set lifter tolerances. That swap would just require finding a donor car to pull the rocker assemblies off of, it would only take about 30 minutes to swap the assemblies. And just to clear things up, when I say mechanical, I mean solid lifters.
If the rocker assembly looks like this then is got HLAs
And if the rocker assembly looks like this then you have mechanical lifters