77 280Z compression

Hello z forum, I need help with my 77 280z stock engine. A little history, I bought this car in a none running condition, when me and my dad pick this car up it was pretty much growing trees out the door sill. We trailered it home and I've been working on it since. What Ive done so far is drained the fuel, replaced the fuel pump & filter(because when I finally got it started it ran for about 2mins and shut of and would not start back up unless I pulled the hose on top of the fuel filter to release the pressure build up,then runs for another 2mins. this was because fuel pump was clogged badly from old sitting fuel.That problem was fixed, now stays running but rough) Next I pulled the valve cover off (because i heard loud machanical noise) and found that four lash pads