On the 3-2v setups:
They may not be too big although admittedly they take a lot of tuning. As you probably know, the 2v carbs' CFM are rated at 3.0" Hg, whereas 4v CFM are (usually) rated at 1.5" Hg. So, a trio of 350cfm Holleys, if rated by the 4v rating, does not flow 3*350=1050cfm, but rather about 750cfm total.
It can get even better:
The smallest 2300 Holley 2v I've found is not the "350" (about 250cfm using 4v rating) but rather the 1-1/16" venturi Holley which I rate at about "265" cfm, or 190cfm on the 4v rating. Three of these carbs would give 570cfm with the 4v rating which is just about the size Tom used on the 292 tests. Not so bad.
I have one of these carbs, it is List 2463, a factory AMC application. These small 2300's dont exactly grow on trees but they are around.
As you said, the little Rochesters are similar. The 283-2v carbs are pretty common and were about "278" cfm (2v rating) or 184cfm on the 4v rating. So a trio of them is only 552cfm.
With three of either the smallest Holley 2300s or the small Rochester 2g carbs the 250 dyno engine should be happy enough, but they are still time consuming to set up unless somebody has already dialed a setup in on their own street engine.
I'm glad the 250 dyno will give us a "Part 2", so much data will come out of this even if Tom can't do all the ideas.
