It has the 671 Diesel, and the 4 speed manual transmission. I don't know who did the conversion, I do know that it has had a few owners since then. We have plans to change the conversion to look less '70s, and hopefully more '50s. I see above that Huskeycamp has provided some folks with info as the where their 4104s came from originally, and I guess that type of historical info is what I am looking for. I am certain I will have more technical questions as we begin to dig in to some restoration.