Damn, you stole my thunder! I was ramping up to start a thread about these.
I was digging around our parts supply and found one of the lower intake manifolds.
I wrote a bunch below about what you have to do to use this, but in summary:
YOU WANT ONE OF THESE.
If you find one, get it with the rail and the injectors.
I haven't checked to make sure it actually clears the hood, as it adds about 2 inches (vertically) to the
manifold height, so it might be close against a hood that hasn't had the stiffening web cut out of it already.
The bolt pattern for the inlet
manifold is identical for all the intake manifolds, there is some modification needed, but looks like it will be much more straightforward than chopping and welding on the flanges and is what I'm planning to do to preserve the injector placement and angle and port mating geometry.
You just need the long bolts that clamp the stack.
I looked into it some and from what I can tell the two piece manifolds came on:
'99 9-5's (ALL, 2.3L and Euro 2.0L cars) (technically they were on MY98 9-5's that the European market got as well)
'99-'02 Viggens (ALL)
Possibly '00-'01 9-5 Aero's with B235R engine - not sure about this one.
The part number is either:
9185844 or
4774477
The accompanying gaskets are on this parts diagram:
There are some modifications you need to do.
The early cars came with the 2 piece
manifold so that there is actually a water jacket that floods the lower
manifold, probably for emissions reasons. You have to weld the port that allows water into the upper
manifold shut, by closing off this passage. You can see the water jacket channels in the side that faces the head.
The little rectangle I'm pointing to in the 2nd photo is the passage that has to be closed.
The little pocket to the left of my finger is where the coolant temp sensor on the C900
manifold pokes through between cyls 2 & 3. You need to drill that pocket to allow coolant to flow into the sensor, or re-locate the sensor to the upper rad hose or the t-stat end of the cylinder head (like where the 9-5 sensor is already).
The ports don't line up perfectly, but with a little material added in by welding and then ground back out the transition is definitely do-able.
The C900 runners come in a little low, but it shouldn't be any different than matching runners together from anything else, and as Luke pointed out the runner side of this flange has rectangular ports.
You also preserve the C900 fuel rail and injector mounting points, so you could actually run two sets of injectors and rails if you wanted to.
Now, my favorite part about this is you can now use the 9-5 style fuel rail, which has some really nice advantages.
The rail inlet and outlet use GM style quick disconnect fittings already that just click on, and there are already adapters you can buy to install Aeroquip style hose with metal GM clip fittings.
You can also now easily get a 3.5 BAR fuel pressure regulator that pops right into the rail.
You also get a fuel pressure check port that taps right into the rail, it's also a GM style fitting with a little tapered seat, almost any fuel pressure guage set comes with this attachment, which is really convenient. It's got a little one-way schraeder valve built into it, it's under the little black screw-on cap in the center of the rail.
You also get the 9-5 injectors, which are like 38lb/hr or something like that already, T5 will play real nice with them already, and they'll support something like 325 whp easy before you max them out.