As a technical point of reference. All the bolts on our motors are "supposedly" metric. Although you will find a 3/8 socket fits the LIM bolts the best for torquing. The threads do follow a close line between metric and standard.

I torque my '95 LIM to 11 ft-lbs.

Buddy
Can you please go into more detail about the gasket not lining up?

Thanks for your feedback Bill Buttermore...ron350....looks like I got to
backtrack and redo.

When I installed Upper gasket per APN install sheet....I noticed it didnt want to
align perfectly with holes on front left corner..off by about 1/8 in. I triple checked
stovepipe to make sure it was true. It was seated in bore fully. I tried bumping it
slightly to see if it made a different on how gasket aligned with intake. It did not
change my offset of gasket. I reset stove pipe/installed gasket to plenum..laid
in place on intake..inspected thru side egr port...looked well centered..
Installed Upper bumping plenum slightly to align front left/tq to 89 in lb per FSM.

My thoughts:

1.Bad Upper Gasket preformed with a slight offset.
2.Incorrect tq value causing my slight offset.
3.Warped intake...If this is even a past problem with these intakes?
4. Am I picking flysh*t out of the pepper? heh..

Thanks again guys.

Before the APN UIM was available, when we were installing sleeves in uppers and shields around stovepipes, we found maybe two in five installations where things just did not line up properly. Archon has experienced this, Mylittleblackbird has seen it, and so have I. We could not determine if the problem was the upper, the gasket, or the LIM. I could check the old posts, but it seemed to me that the alignment resulted in the stovepipe sitting closer to the UIM bore at about the 2:00 O'Clock position viewed from the throttle body opening, iirc. Usually you can move the top of the stovepipe one way or the other by carefully tapping it to minimize the off-center, and as there is a little slop on the UIM bolt holes, they can be loosened and the UIM pushed a bit to improve alignment, as you did. I doubt it has anything to do with torque at these very low values.

Torque specs may vary based on whether the gaskets have crush washers or not. Without them, overtorqing can cause leaks.

The best advice I can give at this point is that if you have crush washers on your gaskets or have the aluminum framed new design, you're probably ok to torque 11-15 ft/lbs.

If your gaskets (off-brand generics) don't have the crush gaskets, go 10-11, and not an ounce over.

Bill...please provide link of past threads on this if you can dig them up..
stovepipe position at 2:00 position...exact same experience here
seemed like once UIM was tq, stovepipe appeared centered
in UIM bore....stovepipe lower shoulder sits at approx 1/32+ above
LIM bore...gasket around it seated....trouble is seating locating pins on
plastic gasket framework to LIM...I even checked tube/straw to PCV port..
which appears to be a possibilty if not centerd correctly.I installed gasket to
plenum and installed as assembly to LIM.

My thought:

1.Measured other stovepipe lower shoulder diameter provided
in APN kit...(.625) hmm...is gasket designed for a better fit with this
type application/install ? (.750 - .625) =

I'm sorry, Buddy, I mis-spoke. Those conversations occurred in PM'* among those of us who were testing new pipes and shields. They have rolled out of my inbox into oblivion.

I do remember in one case cutting off the plastic alignment pins on a UIM gasket in an effort to get a better overall fit. I would not recommend that to others, though, as those pins serve to ensure a good seal on the coolant passages. As I recall, we had problems with alignment on both the newer, smaller .625" stovepipes as well as the older, larger .750" ones. When we had alignment issues, they were usually present with both the older and the newer UIM and gasket, which led us to think that maybe the problem lay with the LIM. It is hard to imagine how that could be, though. We never did figure it out.

The pre owned non-GM plastic manifold and gasket that I have did not want to line up eater.
That is why I wanted to know if the APN manifold is a sleeved Dorman or not.
The plastic manifold I have is made cheaper than the GM and the gasket is about .030 thinner than the GM.
It has Made in Korea molded in the plastic on the bottom.

These are some of the pictures that I took while trying out one of Bill'* options for a sleeve. This is with the new reduced diameter stove pipe installed into the LIM


Then the gasket installed over it.


The sleeve installed into the gasket.


And finally with the UIM installed.


That was an install into a '99 Grand Prix using a Dorman upper, the Dorman reduced diameter stovepipe, and a sleeve from Bill. The sleeve was not attached to the stovepipe.

These pictures are from a 00 Grand Prix using the original GM UIM, and a stovepipe with sleeve attached provided by Bill.




In both cases, the stovepipe is closer to the intake around the 2 o'clock position. However, in neither case was it so far off that I was not able to install the bolts for the UIM through the manifold and gasket, and into the LIM.