99 alero 3.4l over heating ???

just bought this alero that was over heating, the lower intake was leaking so we had it changed, now it has pressure in the cooling system, after filling the cooling system up and we start it, it just spews out the whole its running and smells a little like gas, could it be the head gasket

Welcome to AF.

Most likely bad head gaskets. Pull the spark plugs and run a compression test or a cooling system leak down/pressure test.

i had the compreesion checked they were fine, i went ahead and took off the heads and found that the head gaskets was bad, it was eat up from the water jacket straight to the outside of the block, i have never seen that before, thanks for the help