Justin Posted July 23, 2015 Report Share Posted July 23, 2015 Long time no see, picked up a 2000 Impala LS with a blown 3800 Series II for $150, lots of miles but the body is in nice shape, fully loaded with leather, moonroof, etc. Going to pick up a 3800 Series III out of a '04 GP tomorrow for $200 and was wondering if it's worth the hassle to run the adapters and modify the PCV system to keep the aluminum upper intake, or just buy a new plastic stocker. Any HP gained or lost? Are the Dorman intakes any good, weak points reinforced? Quote Link to comment Share on other sites More sharing options...
Euro Posted July 23, 2015 Report Share Posted July 23, 2015 From what I've seen the replacement UIM's are decent enough, and do not have the warping flaw. I don't think the L26(SIII) upper is really worth the trouble. I know someone sells a TB adapter so you can use the new one with the L36 TB, but I have no personal experience. Back in the day when my GP blew it's motor, GM put in a SIII long block and used the upper intake off of my busted engine. Quote Link to comment Share on other sites More sharing options...
carkhz316 Posted July 23, 2015 Report Share Posted July 23, 2015 Just go with the Dorman replacement. It'll outlast your car. I've used a few of them with no issues. Quote Link to comment Share on other sites More sharing options...
LumiLTZ Posted July 24, 2015 Report Share Posted July 24, 2015 On both of my L36s I am running Dorman UIMs. To eliminate any coolant leaks up there I wound up plugging the 2 coolant ports in the LIM with 1/4 NPT plugs. Since it eliminates coolant flow to the TB, to compensate I pulled the small cover on that end of the LIM and opened up the passage to allow more coolant flow there. In the couple of years since I did it on my pewter LTZ (did it with the boneyard L36 I just got back on the road on the red one as well) i haven't seen any adverse effects (TB icing in cold wx, etc). I figure it gets enough heating being right above the x-over pipe. Quote Link to comment Share on other sites More sharing options...
Justin Posted July 24, 2015 Author Report Share Posted July 24, 2015 Might go with this one for $55, sounds like they have it nicely reinforced and the reviews are pretty decent. Picked up the motor, looks ok but will definitely need gaskets all around before stabbing in the Impala. I suppose I should do lower intake gaskets while I'm in there, valve covers, pan gasket for sure, coolant elbow, anything else while it's out? http://www.amazon.com/ATP-Automotive-Graywerks-106001-Manifold/dp/B000C8T7X6/ref=sr_1_1?m=A2L77EE7U53NWQ&s=merchant&ie=UTF8&qid=1437705222&sr=1-1&keywords=3800+manifold Quote Link to comment Share on other sites More sharing options...
The Guz Posted July 24, 2015 Report Share Posted July 24, 2015 Good time to check the water pump while you have everything out. Quote Link to comment Share on other sites More sharing options...
The Guz Posted July 24, 2015 Report Share Posted July 24, 2015 One more thing is to do this. http://www.grandprixforums.net/threads/46931-How-to-Mod-a-LIM Justin 1 Quote Link to comment Share on other sites More sharing options...
Imp558 Posted July 31, 2015 Report Share Posted July 31, 2015 If I had it to do over again I would put a little bit o Loctite on the oil pan bolts, they loosened up over time and the u bracket makes it impossible to torque them again nicely. Quote Link to comment Share on other sites More sharing options...
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