I just wanted to post a brief follow up here. First of all, thanks to everyone who provided feedback. All of the advice was right on and I was able to replace the LIM gaskets with the aluminum ones from Fel-Pro, and the Dorman UIM was obtainable at a good price, had the updated EGR pipe and gaskets, and everything fit together very nicely.

I would like to say though, that if anyone with a similar problem is thinking about just doing the UIM gaskets and is tempted to let the LIM gaskets go for another time…don’t. As I disassembled the UIM, I was thinking that the gaskets looked remarkably intact for having created such a major engine failure. But as I stripped the engine down to the LIM and finally removed it, I was shocked to see that the LIM gaskets were an utter mess. It may have been the LIM gaskets that actually failed rather than the UIM gaskets at all. They were warped, cracked, and partially melted. Square seals were shaped like hour-glasses in a funhouse mirror and part of the gasket had the consistency of an overcooked radiator hose. So, if I had decided to take a shortcut I’d have been left with a still non-functioning car.

Thought I’d mention a couple problems I encountered too that might help somebody. I should add that the procedure description in the tech section for replacing the LIM gaskets was extremely helpful. That was the only place on the web or in any repair manual that actually mentioned the coolant elbow between the tensioner housing and the LIM. Mine had been overcooked (since the water pump had apparently been failing for some time and the engine was HOT) and crumbled to dust as I tried to pull off the LIM. I had to chisel (very carefully so as not to score the openings) the coolant elbow pieces out of both the tensioner housing and the LIM in order to get a new one in. There was a certain amount of angst involved as nowhere is the proper size given for that elbow and I had to rely on a generic “GM coolant elbow” package and a side-by-side comparison of the pieces of the old one with the new one. Thankfully, it appears to have fit well and is still holding after a week. Also, the plastic sensor housing on the temperature sending unit was so brittle that when I reached in to unhook the wire feed, it broke off with almost no pressure on it so had to replace that. Couldn’t find any torque specs for it so that was another place I had to “best guess” it.

I had trouble getting the aluminum gaskets to stay in place, even with the RTV bead in both lower corners. As I tried to fit the LIM on the coolant elbow, and then slide it into place it took me several tries to get it situated flat, with all the holes in the gasket, LIM, and block lined up, and a couple of times, I knocked the gaskets off. I had lost my helper at this point so was trying to do it alone…and I managed…but it would help to have somebody keep the gaskets steady.

Finally, I have to say that I did not heed advice elsewhere in the forums and take a picture of everything before I started. I also didn’t keep careful track of the sequence that things came apart and I was forced to backtrack a couple times in order to install bracing and frames that needed to be installed prior to other things being assembled (before the fuel rail in particular went back on). Even though I knew how the alternator bracing went on, it was quit annoying to have to undo parts and pieces to do things like run a bolt through a second piece of framing, put a smaller screw in under the larger pieces, etc. So definitely take pictures, the more the merrier, and keep track of the order you take things apart. Even if it doesn’t seem important…it’* amazing what grief ¼” of clearance (or lack thereof) can cause.

In all…lot of lessons learned…and thanks to you guys…The Beast is back on the road.

Forgot to mention...when I had the manifold apart, I put in a 180-degree thermostat as was suggested on these forums, However, temperature guage on the dash still goes up to just a shade under 200 and the engine compartment seems to be extremely hot...almost everything under the hood is too hot to touch after driving. Maybe I'm just paranoid now...but since my newer cars don't get that hot...I'm worried that I may still have a problem.

Glad to hear you got things fixed up, well your t-stat will open at 180 but the fans still are set for the 195 so unless you are driving it would be the same as the 195

and the gauges aren't really that accurate, my gauge was showing over 200 and it was really 185 coming from the laptop I had connected through HPTuners

I forgot to mention, it could be a bubble somwhere in the LIM or the tstat housing, put it on ramps or jacks and rev it to about 3000 RPM a few times and check the level in the reserve bottle, I like to put a little extra in the reserve right after I flush the coolant since I figure some air pockets will get out

Sorry for that, the elbows should be listed and automatic.
Dorman #47065

On the removal etc and gasket installation, the easiest method is to remove the alternator tensioner as it allows you to put the elbows in with it seperately.