I had my engine replaced in my 84 LX 5.0 two summers ago.

I started to notice a ticking that I thought was in the engine but was advised to try replacing the driver side header gasket because the ticking was coming from the center of the engine drivers side. I swapped the gasket today and sure enough the gasket had failed. It was sooted with carbon around two of the ports and rusty in between the exhaust ports. I torqued to specs and let it run 15 minutes, then re-torqued it.

Well the leak on the driver side is fixed and now I can hear it leaking passenger side too. Now that the driver leak (which was dominant) is fixed, the passenger side leak I think is affecting the O2 which is on the passenger side. The car runs at correct RPMs but is running rough and sputters on acceleration, which I know from past experience is the O2 complaining.

So now I have to replace the passenger side gasket which I hoped not to have to do. Theres no room to get hands and tools down there. Does anybody have suggestions on how to approach the header gasket on the passenger side?

My idiot mechanic either didn't torque the exhaust header bolts, or didn't re-torque, when he dropped this engine 2 years ago. The last 2 closest to the firewall were so loose I didn't need a ratchet to remove them. All this time I was sure there was a bad lifter but no.