The targa topped 308 GTS was introduced in 1977 and was made famous on the television series Magnum, P.I.. A notable aspect of the early 308 GTB was that, although still built by Carrozzeria Scaglietti, the 308's bodywork was entirely made of glass-reinforced plastic (or GRP), allowing a very light weight.
The mechanically similar 308 GT4 shared much with the original Dino, and the 308. Both sit on the same tube-frame platform, with a 92 in (2,300 mm) wheelbase for the 308 GTB (the 308 GT4 has a longer wheelbase, being a 2+2), and 4-wheel double wishbone independent suspension. The V8 engine is a DOHC design, with four Weber 40DCNF carburetors. European versions produced 255 hp SAE(190 kW) at 6600 rpm (7700 rpm redline), but American versions were down to 240 hp SAE(178 kW) at 6,600 rpm due to emissions control devices.
The engine borrowed its dry-sump lubrication from Ferrari's racing experience. This lasted until June, 1977, when the 308 was switched to steel, resulting in an, alleged, 150 kg / 331 lb) additional weight. However, a steel-bodied GTB only weighs 12 kg / 26 lb) more than its fiberglass body counterpart. All steel versions of the 308 GTS have a conventional wet-sump engine while GTB models retained the dry sump lubrication until 1981.
Source: Wikipedia (original)