Originally Posted by radomirthegreat
While it'* all taken apart, you should find someone to port/polish the LIM. Get a coolant flush, a couple of oil changes, and see if you can get a non-GM UIM. Here'* one:
See also if GM will provide you with aluminum gaskets.
The zzperformance UIM linked above is NOT the best fix in my opinion. It does not (as far as I can tell) provide a sleeve to act as a heat shield in the EGR bore, and does not provide reduced diameter stovepipes to provide an insulating air gap between the hot EGR stovepipe and the vulnerable plastic EGR bore. These are included in the APN UIM kit described and recommended in the Techinfo article here: http://www.bonnevilleclub.com/forum/...e=article&k=38
The APN kit costs $10 more than the zz UIM, but provides critical protection that is well worth it. Also, APN will ship to almost any US address for $15.
The next best fix is the Dorman replacement UIM because even though it does NOT have a sleeve in the UIM EGR bore it DOES come with a reduced diameter stovepipe that will provide a large air gap between the hot pipe and the plastic EGR bore. Dormans are available at most aftermarket parts houses and sell for $135 to $160.
The aluminum frame gaskets are available from GM dealers who may tell you based on their computer that they will not fit your older L36 engine - don't worry, they will. They are also available from Intense, iirc. Best to call around to get the best price on these - all GM dealers do not charge the same - prices range from $59 - $90. (Someone has to pay for the free coffee and doughnuts in the customer lounge!)