308 GTB/GTS

After the GT4: Pininfarina returns

The 308 GTB debuted at the Paris Motor Show in October 1975 as a two-seat supplement to — and eventual replacement for — the Dino 246, and as a counterpoint to the wedge-shaped Bertone Dino 308 GT4. Where the GT4 was a 2+2 with angular Bertone lines, the new GTB was a short-wheelbase two-seater clothed by Pininfarina’s Leonardo Fioravanti, the designer behind the Daytona, the Dino and the Berlinetta Boxer. The two cars were mechanically related and shared the transverse-V8 tube-frame architecture, but the GTB rode a shorter wheelbase.

The vetroresina years

The most collectible 308s are the earliest. Although built by Carrozzeria Scaglietti, the first GTBs wore bodywork made entirely of glass-reinforced plastic ("vetroresina" in Italian) — the first time Ferrari used the material on a production car. The payoff was weight: roughly 1,050 kg, the lightest of the whole line. Around June 1977 Ferrari switched to steel bodies, which added on the order of 150 kg. Exactly how many fibreglass cars were built is genuinely disputed (see the production claims) — commonly cited as 808, but the marque register and some chassis-range studies argue for ~712.

GTS targa and the carbureted core

The targa-topped 308 GTS arrived at the 1977 Frankfurt show with a removable satin-black roof panel that stowed behind the seats. All GTS cars were steel-bodied and used wet-sump lubrication; European GTB coupes kept dry-sump engines until 1981. Carbureted cars ran four twin-choke Weber 40DCNF carburettors, with European output of 255 PS and US cars detuned to around 240 PS by emissions gear.

Injection, the power dip, and the Quattrovalvole fix

In 1980 Ferrari fitted Bosch K-Jetronic mechanical fuel injection to meet tightening emissions rules, renaming the cars 308 GTBi and GTSi. Cleaner, yes — but slower: European output fell to about 214 PS and US cars to roughly 205 PS, the low point of the range and the reason injected non-QV cars are the enthusiasts’ least-favourite. Ferrari’s answer came in 1982 with the 308 Quattrovalvole (“four valves”): new four-valve-per-cylinder heads pushed European power back to about 240 hp and, as a bonus, replaced the troublesome sodium-filled exhaust valves of the two-valve engines. The QV ran until the 328 replaced it in 1985.

Timing belts / major service. The signature 308 cost. Belts are inexpensive but must be replaced on time; failure on these interference V8s causes valve/piston damage. The real expense is the comprehensive major service typically done with the belts.

Rust (steel cars). Sills, lower doors, rear of front wings and arches, and the black belt line are the usual spots. On vetroresina cars the body won’t rot but the underlying steel chassis can — water traps between body and frame.

Sodium-valve failure (two-valve engines). Carb and GTBi/GTSi engines used sodium-filled exhaust valves that can fail at the head/stem joint. The Quattrovalvole’s four-valve heads removed this weakness — a genuine reliability argument for the QV.

Electrical gremlins. Disorganised factory under-dash wiring, failing switchgear, and overheating fuse-box connections are common and time-consuming.

Oil/cam-seal leaks. Often the result of a car sitting unused; not catastrophic but a maintenance reality.

The injection-era power dip. Not a "fault," but worth knowing: GTBi/GTSi cars are noticeably down on power versus both the earlier carbureted cars and the later QV — set expectations accordingly.

The belt service is the whole ballgame. The 308’s timing belts must be changed on schedule; a snapped belt on these interference engines means serious internal damage. Demand documented evidence of a recent major service. The belts themselves aren’t the expensive part — it’s the full "while we’re in there" job (valve adjustment, cam timing, seals, tensioner bearings, water pump, hoses, fluids) that runs into real money.

Rust on steel cars. From mid-1977 on the bodies are steel and rust like any car of the era — check the sills, lower doors, the rear of the front wings/arches, and along the black-painted belt line. On the early fibreglass vetroresina cars the panels don’t rust, but water can sit between body and frame, so inspect the steel chassis underneath rather than assuming you’re safe.

Electrics are fiddly. Switchgear, the famously messy under-dash wiring, and fuse boxes (look for overheating/melting at the connections) are common trouble spots. Work every switch.

Know which engine you’re buying. Carb vs. injected (GTBi/GTSi) vs. Quattrovalvole changes both character and value. Confirm vetroresina vs. steel and dry- vs. wet-sump on early cars. The QV’s four-valve heads also did away with the sodium-valve weakness of the two-valve engines.

Cam/seal weeps are often a symptom of a car that has sat rather than been driven. Provenance, tool kit, books and a known-specialist history matter a lot on these.

The 308’s pop-culture halo is unusually strong: Tom Selleck’s red 308 GTS in Magnum, P.I. (1980–1988) made the targa shape an icon, and that association still colours the market — a series-used “ROBIN 1” car is a different (and far pricier) animal than an ordinary 308.

As a snapshot rather than a quote (mid-2020s): aggregated public listing/auction data (classic.com) and Hagerty’s valuations put ordinary, sound driver-grade 308 GTS cars broadly in the high-five-figures, with exceptional, low-mileage or documented examples higher, and the early carbureted GTB — especially the fibreglass vetroresina — commanding a clear premium over later steel injected cars. Within the range the rough collector hierarchy runs: vetroresina GTB and carbureted dry-sump cars at the top; carbureted GTS next; Quattrovalvole respected for usability and power; and the GTBi/GTSi injected non-QV cars generally the most affordable way in (precisely because of the power dip).

These are directional, date-stamped observations — not a price guarantee. Celebrity-provenance and rare-spec cars are outliers. Use the Fully Sorted Value Guide for live comps before buying or selling.