The new model was a radical departure from the design philosophy of its predecessor, not only in the mechanical layout, but also in the style of the body, and the chassis construction. Along with the sister 348 tb model this was the first series production Ferrari not to have a separate tubular steel chassis frame. Instead it used a pressed steel chassis, with a separate tubular steel engine sub-frame bolted to it, with the body panels robot welded, and bolted, to the main structure. The wheelbase was 2450mm, and the chassis carried factory type reference F 119 AS on the ts model.

The Pininfarina designed body was essentially the same as the one on the fixed head 348 tb model, apart from the solid removable roof panel, which could be stowed under a cover behind the seats when not in use. Similarly, the interior was virtually identical to that of the concurrent 348 tb model, apart from the stowage facility for the roof behind the seats.

As with the 348 tb this targa roof model was also eligible to run in the Challenge Race Series for the 348 models, in which clients paid a set fee for a safety/performance kit and track support for the season. The 348 ts model ceased production in 1993 with the announcement of the updated 348 GTS, during the production period a total of 4228 examples were produced in the chassis number range 81651 to 96964, which was approximately one third more than the fixed roof model.

The engine was a twin overhead camshaft per bank, four valves per cylinder, 3.4 litre V8 unit, initially with factory type reference 119D, then 119 G, and finally 119 G040 when fitted with catalytic converters. It had a total cubic capacity of 3405cc, and a bore and stroke of 85mm x 75mm, with spark plugs between the camshafts, fitted with a Bosch Motronic M2.5 combined fuel injection and ignition system, which was upgraded to the M2.7 version during the production run. At the rear of the mid mounted engine was a transverse five speed plus reverse all synchromesh gearbox and transaxle unit.