340 issue after camshaft change

RustyRatRod said
I never have used the MP valve adjustment chart. Never have used the EOIC or ABC, XYZ, PDQ or LQBTQA+ method or whatever the hell else there is. I get ONE camshaft lifter at a time on the base circle of the lobe and adjust that valve and move on to the next. Always done it that way and it's always worked well "FOR ME". That means turning the engine to close the valve you're fixing to adjust and turn it "a little" more to assure that lifter is on the base circle of that lobe. Anything else is just too complicated for my simple mind. You have the valve covers off. You can shine a light into the intake valley through the heads and SEE the camshaft lobes and lifters and make SURE they're on the base circle. Simplest way ever to do it, IMO.

This sounds quite easy and makes the most sense. I did use the EO/ IC method and that’s where I think things may have gone south. Pushrods are not too long nor did the valves touch the pistons. It’s not that hot of a cam. Hydraulic lifters we’re not pumped up or filled per Comp Cams instructions. Valves have been adjusted per RustyRatRod method and appear to be fine now. I’ve built a number of engines over my time and this has been a new one for me. Still not sure why the adjustment allowed for the valves to be open just enough to not build compression before. Engine is producing compression and will plan to fire it in the next couple of weeks when I can get back to it. Thanks to those who provided good information.