Interesting find here. I have four lower intake manifolds here:

1992 SSEi, salvaged by BillBoost and Pat
1993 SSEi, stock LIM on the Zilla, heavily modified :P
1995 SLE, stock LIM on the SLEeper
1995 ???, salvaged by LakevilleSSEi

The 92 looks just like my 93. The 95 Nate sent me has a crack running down the 'hump' on the inside of the LIM. This is very likely why the LIM was horrible inside. Coolant leak. Probably also why the ignorant former owner removed one of the ECT sensors and installed a plug. They never knew they were overheating.

Aside from that, there are some REMARKABLE differences between the 92/93 and the 95. However, all the older part numbers have been obsoleted, so it wasn't a MODEL change, but rather a part improvement that obsoleted previous units.

LIMs are marked as such:
1992 SSEi, 24501562
1993 SSEi, 24502104
1995 SLE, 24502302
1995 ???, 24502302

24502302 is the only valid current part number.

So what'* the difference between the 92 and 93?

I've seen the differences between the 92 and 93 and the 95. Very obvious, and I'll post pics later.

This is just a precursor to more investigation, but this may answer some more questions as to why the performance between the 92 and 93 is so different, as well as the 94/95. Keep in mind the larger throttle body and more efficient blower came on the 94/95, but with a smaller pulley. But now it looks like the last LIM change came in time for 95 production.

Hmmmmm.......

Further LIM development work is on hold until I know what the differences are and how they will affect performance. Particularly the 95 LIM.

I knew I was gonna get screwed on this some where....damn 95'* LOL

Anyways, my LIM I sent you is out of a 95 Riviera if you were at all remotley curious.

**EDIT**

Do I need to send out a nother manifold? Seeing that this on is cracked, it'* prolly not worth **** other than R&D, but nothing usable?

I never even noticed the crack to be honest with you, never really looked at that thing at all actually...LOL

The only reason I noticed the crack is because I carefully inspected both units. In reality, neither unit is suitable for use regardless of unknown differences. Corrosion in the sealing and mating surfaces spell coolant leaks. Both of these LIMs spent far too much time in storage, in an exposed condition.

We need LIM'* that have recently been removed, or have been protected by having the SC and all fittings attached.

Both of these LIM'* will suffer from coolant leaks at the thermostat, WP bypass fitting, and heater hose bypass. Regardless of other issues.

The only usable parts on both manifolds combined is the metal coolant bypass fitting the 95 manifold had installed (obviously has been replaced as some point). All ECT'* are also bad (there was only one in each manifold, the 92 had one removed and left open, so the threads corroded in the manifold, and the 95 had one removed and plugged).

Ok,

I'll see what I can dig up with getting another one out to you.

Hold on that. I don't know which one I want now. These differences may help or hurt. I've gotta call in some favors on this problem. I'll post pics of the crack and the differences tomorrow.

Both LIM'* are in the dishwasher right now.

Of all places to wash/store them....

LOL

Ok, lemme know what you wanna do.

The 1994 intake is also different than the 1995. The flow work I have ben doing is on a 1994 intake. It has Part Number 24504502. Willwren, I have a spare 1994 that I would trade for a 1995. My car is a 1995 and the 1994 does not have the same provisions for the sensors.

What'* the differences in 94 and 95 sensor wise?

The only 95 I have is cracked and corroded. Not suitable. And I have sensor locations in the identical positions on all 4 of the intakes I have here. What'* different about that 94?

Yes I am curious about the differnece too, because if there'* a better advantage of a 94 intake over a 95, I'll get another 94 out to you for work when I find one.


That still kinda pisses me off that mine'* cracked......God must hate me or something.