I know we've covered this before, but the
topic of the "generous" exhaust manifolds of the '65 and '66 BIG cars came up recently on the Pure Stock board, and it got me to checking. What I found (and Rick had probably already told me this!) was that the '65 L-78 big cars shared exhaust manifolds with the '65 Corvettes, whereas the '66 L-72 big cars shared exhaust manifolds with the '66-69 Corvettes!
Here is a picture of a set of '66 L-72 big car &'66-'69 Corvette manifolds. And,
here is a picture of what the standard fare 385hp manifolds off a '68 big car. What a DIFFERENCE!
As for the L-72, I gotta tell ya, it may be sour grapes since I sold my LS-6 to pick up a Yenko Chevelle, but I like the 427 better for racing. To me, it seems like the perfect blend: the bore of the 454, with the stroke of the 396.