I'm no expert on 833's but I just found out yesterday that mine is an OD trans, cast iron case and year of mfg 1976. It has the large bearing retainer housing as well. There are 2 different bolt circles and the small housing can be had in both bolt patterns from Passon Performance. Sorry, I don't know how to add a link (what a rookie) but google it, they have US and Canadian distributors. Talked to Jamie Passon and he said it is possible to machine the large one down if you find a machine shop that knows what they're doing. Kev