Im not sure exactly what it will run you cost wise because I work in a shop and dont ask whats being charged for the job etc.. but Ive done a LIM gasket on a Grand Am 3400 basically the same exact engine as the 3100 and It was not that easy, the push rods go through the LIM gaskets and you have to loosen the rocker arms up and take out the push rods. So that means both valve covers have to come off and gaskets need to be replaced as well. Alot harder then doing LIM gaskets on a 3800. You could get it done yourself though if you feel confident enough and have some experience with things like this.
