Brian,
Did you ever test for an intake leak before replacing the gaskets? If not you may just be throwing money away. You need to find the vacuum leak before you determine how to fix it.
If you had a gasket leak, you may have induced a bigger leak if you did not get the gaskets on right, or that may not have been the problem in the first place. The other problem is that it could easily be a cracked intake that shows up when the engine warms up. It can also be something a simple as a cracked vaccum hose, even if it's not the infamous "Cracked Elbow".
I like to use a propane torch and a piece of rubber hose to test for leaks when the engine is idleing. Move the end of the hose all over the intake, gaskets, vacuum hoses, etc. When you bring the hose close to a vacuum leak the engine will suck in some propane and the engine RPM will speed up noticeably. Now you know were the leak is and can figure out how to fix it. Because of the propane, you need to to this outside or in a wll ventilated garage.
That saves you a lot of money you would spend by just throwing new parts at the problem when you don't know what the problem is. That can get expensive real fast.
95% of a good mechanic's work is in diagnosing and testing, changing the part is the easy part. Unfortunately, that's what too many people think. Just slap new parts on and hope the problem goes away.
...Rich
