Also,IIRC, the intake bolt holes are at a different angle on the early 273s than on the 66 and ups; but Ima thinking you're gonna run a later 4bbl intake anyway,so this would be a non-issue.
If you're going from a 2bbl to a 4bbl, you're gonna run into an issue with the Kickdown system and the carb hook up. But there are solutions for these
