Thanks for the kind words, Luke.
Make sure your prospective mechanic knows that you will be supplying the aluminum frame gaskets, the UIM and a new stovepipe when you approach him about estimating the cost of the job. It would probably work out best if you had the parts in hand to show the mechanic so they can see the quality of the parts you are providing. Some mechanics may be reasonably reluctant to let a customer choose the parts they have to work with, especially when customers expect a reasonable guarantee for the work provided. If the mechanic can see what he will be working with, he will be much more likely to agree to do the job for you.
Many shops factor in a profit on the parts they provide, and can thereby offer you a lower labor rate when they charge you retail for parts they obtain at wholesale. If you supply a majority of the parts, they will need to know that up front in order to calculate a fair profit for the job. If their labor rates are up on the wall, they may hesitate to perform the work because they cannot maintain their profit margin without increasing the published hours or cost of labor.
My recommendations for UIM/LIM repairs for the 95-05 L36:
Please note that if you cannot wait for parts in the mail, you will not get the best fix.
The best fix for the LIM - GM aluminum frame gaskets......$59
The best fix for the coolant elbow(*) Dorman Help.........$6
The best fix for the UIM - APN upper intake manifold kit......$115 including shipping
In addition, I recommend the following steps to keep engine operating temperatures down, to ensure that coolant flows around the hot stovepipe area in the plastic UIM, and to eliminate any possible harm from the use of Dex-cool - all factors that protect and extend the life of the UIM and LIM gaskets.
Flush coolant and re-fill with "mixes with any color"
Drill a 1/16" hole in a 180F thermostat flange and refill according to: http://www.bonnevilleclub.com/forum/...=article&k=100
Install an after-market transmission cooler.
I use only a scraper and degreaser to clean gasket surfaces on the cylinder heads to avoid introducing abrasives into the engine. I use blue loctite on the LIM and UIM bolts.
I remove the exhaust crossover for better access to the throttle body bolts and easier removal of the LIM.
Regarding the UIM, the longest-lasting fix will come from an upper intake manifold protected by a heat shield and the use of a reduced diameter stovepipe to provide an insulating gap between the hot stovepipe and the metal heat shield. The only commercially available kit that provides those features is from APN. Dorman UIMs have NO heat shield protection for the plastic EGR bore, but rely solely on the insulating gap provided by a reduced diameter stovepipe.
UIMs can be sleeved, plugged, and otherwise repaired for re-use, and these repairs can be made at low cost. But, unless the UIM is fairly new, most will typically exhibit warpage at the throttle body sealing surface and at the coolant passage sealing surfaces around the EGR bore. When considering repair of a UIM, don't forget to add the costs of a new UIM-LIM gasket and throttle body gasket, typically about $45.
From Sears, a smaller 3/8" drive deflecting beam type torque wrench does just fine for UIM/LIM work. It costs $25. http://www.sears.com/sr/javasr/produ...id=00944690000