The 1968 Firebird was little changed from the 1967, the biggest and most obvious one being the elimination of the side vent windows on the later car. One-piece side windows are the quickest way to tell a you’re looking at a ’68. Another dead giveaway are the front driving lights. On the ’67 they face the front only, but on the ’68, they wrap around the front corners of the car, extending into the sides allowing them to double as side marker lights. Side markers were a Federal requirement from the 1968 model year onward, so this served the front nicely, and the rear fenders were adorned with side marker lights that were shaped like the Pontiac logo. Lastly, 1967 was the last year for the 326 small block. For ’68, it was bored out to 350 cubic inches, and thanks to the engine call-outs (the engine displacement badges on the hood), if it says 350 on it, it’s a ’68. Many other minor changes differentiated the two years, but these are the main ones, and the most obvious.
VIN CHANGES FOR THE 1968 PONTIAC FIREBIRD
Per new Federal law, all VINs had to be placed on the dash visible through the windshield, even when the car was locked, so, the Firebird’s VIN plate was removed from the front left door pillar. Also starting in 1968, Pontiac began stamping the VINs onto the engine blocks and transmissions, much to the benefit of collectors. This is what they mean by “Numbers-Matching”.
1968 PONTIAC FIREBIRD
COMBATTING WHEEL HOP
To combat the never-ending problems with wheel-hop (rear axle spring wind-up), particularly on the higher performance versions, multi-leaf rear springs replaced mono leafs on all but the base Firebird, and the rear shocks were staggered, one in front and one behind the rear axle.
1968 Pontiac Firebird INTERIOR
1968 PONTIAC FIREBIRD INTERIOR CHANGES
With the elimination of the vent windows, cabin ventilation needed to improve so GM added a flow through system they called Astro Ventilation to both the Pontiac Firebird and the Chevy Camaro. This required the addition of ball-and-socket chromed vents on either side of the dash, just like the air conditioned cars had, but now they all had the vents, AC or not. There were also new molded door panels and on Custom interiors, expanded vinyl seat inserts and burled woodgrain for the dash and console.
1968 Pontiac Firebird ENGINES
326 GETS PUNCHED OUT TO A 350. The big news for the 1968 Pontiac Firebird line was the boring out of the 326 small block V8 from 3.72” to 3.88”, yielding 350 cubes. Horsepower for the base motor rose from 250 to 265. The 350 H.O. (High Output) rose from 285hp to 320hp, a 35hp bump. This wasn’t due to the added displacement alone, there were new better-flowing heads, a hotter cam, and a new carburetor as well
HOT NEW 400s FOR THE ’68 FIREBIRD. There were now 3 versions of the top-line 400 V8, all with 4.12 X 3.75 bore & stroke and now all with 10.75:1 compression ratio. The W66 version made 330hp at 4,800rpm. The L74 HO version with wilder cam produced 335hp at 5,300rpm. It could do 0-60 in 5.3 seconds and cover the quarter mile in 14.2 seconds. The L67 used the 400s hood scoops (blocked of normally) to feed the cold air induction system, producing the same 335hp as the L74, but at a lower 5,000rpm. It’s 0-60 time was a blistering 4.8 seconds, but the quarter mile time actually went up to 15 seconds. Still very fast.
FIREBIRD SPRINT OHC ENGINE UPGRADES. The two OHC (Overhead Cam) 6 cylinders were stroked from 3.25” to 3.53”, taking the displacement from 3.8 liters to 4.1 (250 cubic inches). Previous OHC 6s used the same crankshaft and connecting rods as the Chevrolet 6 cylinder. But the longer stroke was accomplished with all Pontiac parts. The Sprint version got a new 10.5:1 compression ratio cylinder head, although its output remained unchanged at 215hp.
1968 Pontiac Firebird VIN Decoder
In 1981, all vehicles sold in the US went to a 17-digit format. Prior to that, every manufacturer had their own system. GM used a 13-digit system for all GM cars & trucks from all Divisions.
1st DIGIT – GM Divison (2 = Pontiac)
2nd & 3rd DIGITS – Model (23 = Firebird)
4th & 5th DIGITS – Body style (37 = Coupe; 67 = Convert)
6th DIGIT – Year
7th DIGIT – Assembly Plant
Last 6 DIGITS – Serial Number of Car
1968 Pontiac Firebird Production Numbers
OHC 4.1 6cyl
OHC 4.1 6cyl Sprint
350 H.O. V8
*** Numbers indicate the total production of 350 HO and 400.