Can You retrofit a Pontiac 455 into a 69 Grand Prix?
Interchangeability between Pontiac engines is vast and common, so retrofitting a 455 into a ’69 is not unusual. The six years of 455 production leaves more used parts around than the three years that 428s were built.
What was the difference between 1969 and 70 Pontiacs?
The only major change between ’69 and ’70 cars was in the engine: The 428 was retired for good, and the new 455 introduced. Coming in only one delicious flavor, the 370hp 10.25:1 compression mill was more of what Pontiac was known for: power.
What did the Pontiac GTO 455 look like?
The front fenders and rear quarter panels were given striking “eyebrow” contours, sweeping nearly from the nose through the doors and picking up again over the length of the rear panels. While the 1970 Pontiac GTO 455 certainly didn’t lack power, many muscle car enthusiasts recognize the model as a missed opportunity for GM and Pontiac.
When did the Pontiac Grand Prix come out?
It was a big showroom success, too, with Grand Prix sales up an astonishing 225 percent over ’68. Even the SJ model pushed big numbers; over 10,000 sold. Then it got even bigger, when, in 1970, Pontiac rectified the engine lineup and brought out the new 455.
Is the Oldsmobile 455 a small block engine?
For this reason, you often find an Oldsmobile 455 under the hood of a 1975 or later Buick model. In 1966 Pontiac really didn’t have a small block engine. In an effort to keep things simple Pontiac designed all their V-8 engines around the same casting.
What kind of engine did Pontiac make in 1955?
In 1954, General Motors leaned heavily on Chevrolet and Pontiac to develop V-8 engines for the 1955 model year and provided them with all available resources to ensure success. Pontiac settled on a 3.75-inch bore and 3.25-inch stroke to produce a 287-ci package.
What kind of engine did Pontiac have in 1966?
In 1966 Pontiac really didn’t have a small block engine. In an effort to keep things simple Pontiac designed all their V-8 engines around the same casting. Even the small displacement 326 CID motor is considered a big block. Therefore, the 389 Tri-power Trophy engine is also based off of the 326 block casting.
What’s the difference between a Pontiac 400 and 455?
Although you could still get a 400, you could also get 455 HO. The 455 HO is a bored out version of the Pontiac 400 HO. In 1970 Pontiac increased the displacement in an attempt to make up for reduced compression required by new government regulations. Engineers did their best to squeeze out as much horsepower as they could.