yeah im not sure if had lim issues because coolant never leaked but i was smelling gas coming from up front when starting up and shutdown. So i replace the rear valve cover gaskets and gromits, installed ported lim uim with hv3. used gm gaskets for the lim and felpro for the uim and rear valve cover(sucks because i got some aluminum valve covers so ill redo the rears and do the front next time).

 

Funny thing also i found a leaf in my lim i didnt know if it was canadian thing lol. i shoulda kept it, it was pretty well preserved in all that black soot

 

Based on your LIM pics, the gasket was on it's way out, it was only a matter of time. You can see the nylon around the coolant ports collapsing. When you got the GM gaskets, were they nylon LIM gaskets? If not, you really should have opted for the FelPro aluminum gaskets (they should pretty much last for the rest of the life of the car).

As for aluminum valve covers, I am using 3800 F-Body valve covers that have been cleaned up and polished (only factory 3800 Series II to NOT use plastic covers).

Here's a link that kinda shows them and explains how I handled the front spark plug seperator:
'04 Monte Carlo SS - Multiple Mod Install

 

yeah used the gm aluminum gaskets that they changed to in 2005.

How'd you clean and polish your valve covers?

 

I cheated, I bought them that way. My valve covers are form the F-Bodies that were aluminum and a guy on eBay had already cleaned/polished them and decided not to use them.

I'm (slowly) working on a set of 3100 aluminum valve covers to replace the ones on the grand am. Lots of work with fine grit sanding pads and dremel bits. First cleaning the rough spots in the castings and then trying to feather them to a smooth finish (I am far from a master, my work on the 3100 covers is all experiment with NO research and then I'll pop them on my Grand Am to replace a cracked plastic cover).