No on the Cat 3412's, most if not all these 58C's had DD16V92's. I believe the 12's were standard but I've never heard of one with them. I've run a few 58C's and can state fact, that they are Heavy, Ride Heavy, "Like your Pulling a Trailer", but will go through anything. Very strong, quality, heavy sea boat, solid and awsome in a big sea. Side by side with a 65C they're nearly identicle in, Height, and Beam it's just the 65 is 7 feet longer and possibly why it runs just a touch better, the added hull length keeps it from squating as easily when backing off the throttles. If you live in an area of the world where draft doesn't matter, and you can afford 125GPH at a high cruise rpm then a 58C would be great boat. Almost a 65C for half the money, definitely worth it.
I'm not 100% sure why there weren't as many 58C's built compared to the 65C but an educated guess would be this. Very similar size but, deeper, identicle operating and Maintenance costs, and a 65C was NOT much more expensive to buy when they were new. As a buyer if you can afford a 58C you can a afford a 65C so why not buy the 65 with a half a foot shallower draft and a 4th stateroom option. Hatteras didn't offer the 4 stateroom midship master until later years BUT, you could get a 4th crew stateroom just forward of the engine room where the A/C pump room is typically located. With that option they moved the A/C units outbord the motors. In my opinion as great of a Sea Boat the 58C is, the 65C just over shadowed it, and for only a little more money. Same situation I believe killed the Late Model 64C so quickly. Why buy the 64C when the 68C isn't much more expensive to own with a roomier 4th stateroom, same power, same speed, and same operating costs.
The 58C is a great boat for the right person, in the right area of the globe at ANY price. But if a great deal on one pops up it could be a great Boat for the right person Anywhere. That's why I posted this thread, I don't know the boat but if the rest of it's in good condition there is possibly a great deal for someone looking for a big Hatteras Convertible.
Tony.