My original upper developed a small leak so I reasoned, while I'm in there I should
do it all at the insisting of the BC club members. I'm glad I did!

the one that most people use at clubgp is from zzperformance, and is for the */c throttle body - meaning that you have 109 dollars for the adaptor, 130 ish for the upper intake (with shipping, from gmpd), and anywhere between 30 and 200 for a s2 */c throttle body. i've got some drawings made up for the n/a throttle bodies, but our biggest issue is with how our TB flares out just before the intake... makes it tricky to get a nice fit in there that won't cause more turbulence than what it'* worth.

i'd really like to get this done to my car to be the *i can't spell it right* pig so that it'* finally out in the open for others here to do, but the money isn't quite there right now... always seems to flit away at the worst possible times. with any luck (and that'* about what it will take), i'll be able to divert money set aside for some suspension stuff (new struts) to get this hammered out.

posting a new thread here in a second to ask you all a q about an adaptor...

I replied to your other thread first without even looking here to volunteer to be your guinea pig! PM me..

If I could get 80 - 100K out of my original intake and same or more out of the improved replacement....Why spend all that money?
Your car certainly isn't going to strand you even if it looses a tablespoon of coolant.

Question: If I can obtain a used throttle body for a '99 supercharged car, will all the various sensors, etc., on my L36 hook up to it without modification and without turning on the CE light? That would seem to be the obviously cheaper way to use the aluminum upper manifold, and with the money saved buying the adapter might make a better and cheaper alternative.

And how does the supercharged TB differ from the n/a one? Bigger bore, what?

Thanx.

I retorqued my upper intake this morning...

Boy, was I surprised at what I found. All of my bolts were only at 40-45 in. lbs. of torque! They had all loosened up or I never tightened them properly in the first place. The stud that holds the EGR shield in place was very, very loose. I pulled it out and it was coated in coolant. That area is EXACTLY where my leak was coming from.

So, I used the blue Permatex thread locker on all 10 bolts and retorqued everything down to 89 in. lbs. in the order recommended in the Chilton'*. Time will tell how it works out...

In the mean time, I'm still interested in that aluminum upper...

I retorqued my upper intake this morning...

Boy, was I surprised at what I found. All of my bolts were only at 40-45 in. lbs. of torque! They had all loosened up or I never tightened them properly in the first place. The stud that holds the EGR shield in place was very, very loose. I pulled it out and it was coated in coolant. That area is EXACTLY where my leak was coming from.

So, I used the blue Permatex thread locker on all 10 bolts and retorqued everything down to 89 in. lbs. in the order recommended in the Chilton'*. Time will tell how it works out...

In the mean time, I'm still interested in that aluminum upper...

even if you obtain the TB from a */c car, you're going to need an adaptor. right now, the only one available is from zzperformance, for 109 dollars. i believe (but am not positive, as i accidentally purchased a s1 l67 tb instead of a s2 one) that the sensors are plug and go, but im not sure.

as for the differences in the tb - they are not great. the main two differences are...

1. our tb spreads out at the very end to match up with the opening of our upper intake - the l67 is a straight shot - a very nice cylindrical shape. much easier to adapt from.

2. the bore of the l67 tb has a few millimeters over ours. *from memory* the l36 tb is some 68 mm, while the l67 is somewhere around 72 (again, from memory, i'll check it on monday).

personally, if we had a source for cheap l67 tb'* i'd much rather kit those, as it would provide a nice little boost in performance, but finding them cheap is hit or miss... and you can't base a price of a kit on hoping that you'll always be able to find the lowest cost TB... you have to base it on a price of what you know you can get. and about the only guaranteed supply of throttle bodies (gm) costs a couple hundred....

<on topic>

good luck with the retorque. when I did my gaskets, they all got some water proof locktite...

OK, just swapped out the throttle body gasket and it was easier than I thought. It was obviously leaking at the bottom. I've just reinstalled everything but, left out the thermostat for a few days with radiator flush in the car. I will reinstall the thermostat and add new coolant after the six hours recommended engine running time for the flush.

I reached insiide the upper intake and ran my finger around, and shone a flashlight in as well. No coolant leaks, but the intake side of the throttle body and manifold had a fairly heavy greasy buildup, which I washed off with lacquer thinner, and then greased the outside (I've had some initial throttle sticking off idle whcih didn't go away with greasing the cable; now it'* fine).

I'm going to buy the aluminum upper from the Series III and see what I can do with an adapter myself. I have a friend with a Bridgeport.

I am quite tempted to do what ron recommended, just plug the water passages to the throttle body with pipe plugs, but I want to see what I'm dealing with first.

By the way, I'm going to use the green stuff for the new coolant. I just hear too much bad press about DexCool.

Thanks to the remarks in this thread, I will also retorque the upper manifold bolts after adding the coolant.

11 ft pounds, right?

Thanks to all!

89 inch pounds if memory serves.

read my rant in the other thread about coolant passages.

and i wouldn't be afraid of the dexcool at all... it'* good stuff, and it'* what your cooling system was designed to run.