Which bellhousing would be best

The early A cast iron bellhousing was for a 122 tooth flywheel and 9.5" clutch.

Those transmissions you have require different bellhousings. The standard 4 speed for the cast iron bell will have a 4.35" retainer. The OD transmission has a 5.125" retainer.

The bearing retainer is what centers the input shaft, not the bolts holding the transmission to the bell. If you want to use the OD bellhousing with its 5.125" bearing retainer opening with the earlier trans and its 4.35" bearing retainer, you MUST use an adaptor to make up the difference. You may be able to buy an adaptor ring from QuickTime or one of the aftermarket bellhousing manufacturers, as they usually make the opening 5.125" and use an adaptor because there are several different bearing retainer sizes for the 833 trans.