Hence the dilemma with conflicting info , and trying to get ground truth from 53 years ago. The Chrysler letter documenting the introduction of these cars stated they would have standard size street hemi carbs modified for better fuel distribution. This is a Feb67 letter. The Chrysler race manual does not talk about the 67 RO/WO cars at all.

Carter show the "Drag Strip" package carbs (limited production) 4345/56 on a Sep66 Form as part of the normal Chrysler 67 carb data. So they must have been planned for these cars. Also they were over the counter in later years as I have seen 70 date code carbs.

If NHRA disallowed them, how did owners get legal carbs modified to work with a Vanke modified manifold?

One thing I did see in race manual for inline using the rat roaster manifold was removing distribution tabs on the street hemi carb besides jet and rod changes.

Which get back to the carb set I have that supposedly came from a 67 Belvedere Race car. 66-67 Manifold modified like Vanke. Carbs that are modified with distribution tabs removed, larger .107 and .104 jets and staggered rod. They have stamped serial numbers also which seems odd to me. So are these just modified parts a racer did, or could these be Chrysler modified for the 67 SS cars???