My order from GMPD, placed 4/11 finally got here (I had a few words with them about waiting 23 days from the time I ordered to receiving my parts). One of my purchases was the l26 UIM (that'* right - get ready for it ); but the other was a set of lower intake mani gaskets... I did them when I did my upper back last June, but figured as long as I was down there, I'd pick up a new set and see what the old ones looked like after a year of use.

Low and behold, the lower gaskets have been improved!

I'll have pics later, but as a teaser, they've now put metal inserts (that'* right, metal inserts) around all of teh circular passages, and the rubberish gasket material used for the main ports has been changed to a higher temp composition! Good news all the way around, if you ask me. If it'* been said here already, my apologies - I've been running around a lot lately and haven't been on in a while. Pics later tonight -

p.*.

89017400 is the part number...

Thanks for the news! That'* fantastic! With new LIM gaskets and the modified EGR stovepipe (or aluminum upper in your case) we'll be up and running for years without major failures. It'* about time they did something about it.

pics -

old LIM gasket - the one removed a year ago, and the (then) gm replacement.


new LIM gaskets, same angle


new LIM gaskets - metal inserts


and of course, some teaser pics...

Wow! Very impressive. Don't forget to keep me in mind for the second L26 mani! I'm local and anxious to get it on. I'm sure my lowers are getting kinda deformed by now (have 50K on them). Upper is leaking externally slowly again..

Vital, there are other websites dedicated to that type of thing. Stop hitting on BC members you leg humper


I didn't know the L26 UIMs still had composite runners. Is that pretty common for other engines too?

LMAO!!!

Good call!!! I like the local talent!!

i don't know if it'* common, but when they designed the sIII upper intake, the main goal (it seems, anyway) was to maintain all series II items below the mani itself - same egr pipe, same gaskets, same lower intake, etc. I threw a series II UIM gasket set on, and as I expected, it fits like a glove.

anyway, back on topic, I looked at the drawings in great detail while I was getting ready for this project... and any time you have an assembly (which is what the upper is considered, as it has two studs in it, and the runners), it lists the individual parts that are included. well, the intake runners remain 100% unchanged from their series II days - you could take the plastic ones out of your sII and throw them in, wouldn't matter.

and in the grand scheme of things, i guess it really doesn't matter - the old ones stood up to the heat and stuff just fine (though they could get pretty grimey). and that means the general doesn't have to set up a new process for a piece that works fine anyway - they just got their metal around the area where it counts - the EGR.

Anyhew, that was a really long response to say that they're the same runners that were in there before... sorry about that. . I'll be getting on that adapter, and hopefully will have the first try-out of it by the weekend. I've moved on from machining from a solid piece of aluminum to casting of the adaptor plate. Should actually be a lot cheaper, and easier to do in the long run. I'm setting up my furnace for the melt this week (as in, I'm building it today, and hopefully it'll be ready for a melt by friday), and I've got the materials to make the mold (i'm doing lost foam casting, btw), so I'll work on that while the materials in the furnace are setting up. We'll see how the lost foam goes, and if it turns out alright, I'll make a bunch of them for you guys. Shouldn't cost very much at all when I'm all said and done (if it goes according to plan). If I can find my aluminum cheap enough, I imagine I could ship kits (with adaptor and mounting hardware) for 25 bucks or so... but we'll see. and vital, i'll do my best to guess at whether this will work with a stock airbox or not - I'll have to have theJMFC bring my over from his house (left it in his garage when we took it out). With any sort of luck, in a week and a half I'll be up and running... weather permitting...

Yes keep us posted.

YES keep us posted.