so. not meaning to jack Bob's post at all. but what are the benefits of longer skinnier runners, over wide short ones?

and what hypothetically would be a good dimension for runners on a 3x2 for a 292.

1967 Chevy II, 2-door post.
250, 3-OTT.

1969 GMC 1/2-ton.
307, 3-OTT.
DD.