Do I Need a Bushing for the TC for a 273/318 Swap?

I get it but this has been discovered before. I don't remember where but when we encountered this we searched and found discussions on this with the same results (including this forum iirc). The ones we dealt with were unturned factory 340 cranks that were early 67 with small registers. The assumption is the factory must have carried over the 273/318 cranks small register for a limited number of early 67 built 68 340s. It was chrysler lol, look at the stuff they have done.