Short of Paying Joel for confirmation....

[427TJ]

I assume that Motion would happily convert any car brought to them. I was part of the COPO/Motion thread and someone said that the COPO-appearing '69 Camaro SS 427 in that thread could have been a 6-cylinder before conversion. It seems silly to order a 6-cylinder '69 Camaro and then have to add not just the 427 but a tranny and 12-bolt, etc., but it could have happened.

I think the most common route was to order an L78 Super Sport car through Baldwin Chevrolet (with whatever options you chose) and then Baldwin would deliver it to Motion for the conversion. You then took delivery of the converted car at Baldwin.