[BMac]

Hey, that's a good move dividing the plenum into a dual plane but remember, it's best to divide by firing order! That way the pulses go left right left right left right.
My friend has a Toyota wagon with a 1.8 and I was surprised of the torque it had so I asked him to open the hood. Sure enough, long runners and a divided plenum!

I think with the constant vacuum type carbs like the Predator/Kendig you won't have to divide it's plenum. In fact, you may not have to divide any plenum. Not sure on that one. I have both those carbs and also a Woodworth constant vacuum carb. If I was running a straight engine, I'd use motorcycle carbs like the Keihins used on Hondas. Actually the older Honda Preludes used two Keihin carbs used on their bikes.

Just a thought but it may be worth a shot.