Which bellhousing to use?

I am converting my 70 dart 340 from auto to 4 spd. I recently purchased a '76 A-833 O/D. I have been doing some research, but still have a few questions. I know if I use an older bellhousing I will have to bore the bearing retainer hole to 4.80 and downsize the retainer on the trans. to 4.80 and it would work on my '73 motor and '70 body. But if I use an O/D bellhousing, will it bolt correctly to my motor? I really dont want to have to machine an older housing and im worried that if I use an O/D bellhousing it wont work. I imagine that either bellhousing will bolt to the O/D with the exception of the bearing retainer right? I have links on brewers to the two bellhousings I am looking at. Appreciate any help. Thanks.

http://www.brewersperformance.com/proddetail.asp?prod=BH482

http://www.brewersperformance.com/proddetail.asp?prod=BH859