Unless I am mistaken, there's no difference between a standard A833 and the OD A 833 in terms of the bellhousing. I have a SB unit, 9-1/2" clutch, casting number 2465523. It shows as a 64-66 unit for a 273. I'm not any kind of SB wizard, but I'm sure someone smarter than I am - which is just about everyone - will chime in if this will fit.