We've used a couple truck bell housings as they are usually much less expensive than a passenger bell housing. The truck has a bigger bearing retainer hole than a standard passenger housing does(way bigger than the small '63 retainer). We got the larger bearing retainers from Kajun John. Here is a link to his web site http://www.kajunjon.com/ I believe he was also selling them on Ebay and I think he listed them as a bearing retainer adapter for a truck bell housing.