A 4 bbl. manifold has a slight advantage in that the open flange is big enough that you can make fuel dams out of popsicle sticks, carve drains across the front of wet cylinders, partially mask port runners, etc. across the plenum floor where a 2 × 1 etc. would be inaccessible.
Except it's a lot of work, and going by plug color is far too crude to be effective. You need EGT sensors, etc.
