I've been reading up on the DIY log intakes and all the info I can find appears to be for setups running two plenums with 3-4 carbs on each side. This is the site I've been looking at for how long to make one http://victorylibrary.com/mopar/log-c.htm does the general theory apply for a single one? I'm looking to make a 3x2 intake for a 331 hemi. Has anyone made one that could share measurements/dimensions or could point me in a direction that could help in the construction of one?
I'm no expert, but common sense theory tells me that the Chevy TPI and alot of other race-fab'ed intakes use the same configuration that you're talking about: a single square-sh plenum with runners to the intake ports. The fabricated ones I've seen have a "V" shape at the bottom that meets the angle of the cylinder heads.