Vehicle Sighting - 1975 Chevy Impala Custom

[Astro14]

Had you gotten it new?
Neighbor had some huge Pontiac wagon of that era with a red "400" in the left grille.
Different division but likely the same motor. Thee family said it was a pig.

That era, 1970-1976 would’ve been a 400 Pontiac. Different engine altogether.

Same block as the 455 Pontiac. A good, stoutly built engine, capable of lots of power, but hamstrung by low compression and small heads to meet emissions regulations.

Moving a wagon of over two tons, which included retractable rear doors and glass, through a three speed automatic was a lot to ask of that low compression engine.

1977 was when GM began sharing engines across brands.

1979 was when GM lost a lawsuit on their failure to disclose engine sharing.

In 1977, you could get an Oldsmobile with a Chevy 350, instead of the 350 Olds. People who paid extra for an Oldsmobile 88 or 98 over an Impala were none too happy over getting the “cheaper” Chevy engine.

 

[Number_35]

That era, 1970-1976 would’ve been a 400 Pontiac. Different engine altogether.

Same block as the 455 Pontiac. A good, stoutly built engine, capable of lots of power, but hamstrung by low compression and small heads to meet emissions regulations.

Moving a wagon of over two tons, which included retractable rear doors and glass, through a three speed automatic was a lot to ask of that low compression engine.

1977 was when GM began sharing engines across brands.

1979 was when GM lost a lawsuit on their failure to disclose engine sharing.

In 1977, you could get an Oldsmobile with a Chevy 350, instead of the 350 Olds. People who paid extra for an Oldsmobile 88 or 98 over an Impala were none too happy over getting the “cheaper” Chevy engine.

I remember there being quite a uproar over people buying Olds cars and feeling cheated they'd gotten a Chevy 350.

Probably a bigger deal in the US, as here we were used to Pontiacs with Chevy engines.

The other GM scandal at that time was their using TH200 transmissions, intended for Chevettes, in larger cars. A lot of these failed prematurely.

 

[Snagglefoot]

If I remember correctly the Oldsmobile 350’s had valve rotators.

 

[Duffyjr]

I remember a buddy's parents bought the wagon version of this and it was huge, it barley fit in their garage.

 

[Snagglefoot]

Had an uncle with a 455 Oldsmobile and a teacher with a 455 Buick of that vintage and series.

 

[PontiacHO]

In the early 70's if you ordered a 400 with a 2 bbl carb you got the small block. If you ordered the 4 bbl you got the new 402 big block.

In 69 you could order a 396 with a 2 bbl. But no 400 small block as it didn't come out till 70.

You are correct. There was a lot of confusion due to the 70 Chevelle marking a 402 big block as a 396 and the Impala marking it as a 400. Then there was also the 400 small block as well.

 

[Number_35]

You are correct. There was a lot of confusion due to the 70 Chevelle marking a 402 big block as a 396 and the Impala marking it as a 400. Then there was also the 400 small block as well.

A few years ago I saw a mid-'60s GTO badged as a 6.5 l (which conveniently comes out close to 400 cubic inches).

 

[PontiacHO]

The 402 was a bored 396. (Big block)

The 400 was a bored and stroked 350 (small block)

Despite many who complained about the 400 being unreliable*, it lasted over 200,000 miles in that car without any work on the Dino oil of the day. It was a good engine.

It put up with two teenage boys (myself and my brother) learning to drive, including one teenage boy who had a penchant for pushing machinery to its limits. That poor Impala was driven very hard on many occasions.

*it had two bolt main bearing caps, so you couldn’t build it for a ton of power without upgrading those. It also had adjoining cylinder bores, which required different heads for decent coolant flow.

There were 4 bolt main 400 blocks but they were actually weaker from a high performance perspective due to the extra bolt holes in the thinner crankshaft/main bearing saddle to accommodate the 3.75 stroke.

Better 2.02 heads could be used if corresponding steam holes were drilled in the heads using the 400 head gaskets.
The 400 showed it’s weakness if they were ever overheated. Those Siamese cylinders would “sink” due to thin wall distortion.

Aside from that most 400s that were used in a racing build up were drilled and machined for 4 bolt main caps had the outer bolt holes in the blocks at an angle for strength. They wouldn’t weaken the block like traditional main cap bolts holes drill straight in.

400s also were externally balanced, had 3 frost plugs per side, and were never upgraded to a “high performance “ version from the factory.

They are really rare these days. Would love to have one for a mild street build. A good 400 small block will hang with a 396-402 in most ever application. Less weight. Parts are cheaper vs big block.
They have to be bored and honed with a torque plate to ensure cylinder roundness and ring seal.

 

[Kira]

I had the T200 in a '76 Nova 250cid. Shifted OK but the piston for reverse actuation cracked and leaked.
The car could go backward on level ground only.
My transmission shop put a T450 into my Nova. That, and a driveshaft refresh, gave me "the boulevard ride".
That Nova was a hodgepodge. The interior was red and black vinyl and it had a 25 gallon tank.

 

[wag123]

In 1977, you could get an Oldsmobile with a Chevy 350, instead of the 350 Olds. People who paid extra for an Oldsmobile 88 or 98 over an Impala were none too happy over getting the “cheaper” Chevy engine.

The Olds 98 was never produced with a Chevy engine. In 1977 the Rocket 350 was standard and the Rocket 403 was optional. The only 1977 Oldsmobile that got a 350 Chevy engine was the 88. Old school Oldsmobile customers were madder than mad! If you wanted a Rocket in the 1977 88 you had to get a 260 or 403.

 

[SatinSilver]

I posted this one before, 1974.

For sale most of the summer for $5500. No hint of rust, white leather interior, original patina to it, recently serviced, not sure about the miles since it wasn't listed. Which was kind of strange when all this other info was given.

 

[drtyler]

I posted this one before, 1974. View attachment 125203View attachment 125204View attachment 125205View attachment 125203For sale most of the summer for $5500. No hint of rust, white leather interior, original patina to it, recently serviced, not sure about the miles since it wasn't listed. Which was kind of strange when all this other info was given.

Perfect car for someone with SatinSilver screen name!

 

[PontiacHO]

Longer than a Chevy suburban!!

 

[addyguy]

Neighbours years ago had a 74-76 Impala 9-passenger wagon, brown with brown interior.
Big family, and they spent their summers tent-trailer camping all over with this wagon, plus daily life use.
I talked to him years later, and he said it was a fantastic car, and it had ‘hundreds of thousands’ of miles on it when it finally let go on the highway when it was like 15 or 17 years old.

 

[carviewsonic]

A good friend back in college days had a '73 Caprice, same body style but with fender skirts, dark red with white vinyl top and dark red interior. Had a rebuilt 400 with duel exhaust. It was a nice car but he only had it for a couple of years, said it was too hard on gas and traded it on a new S-10 pickup, which gave him endless problems.

 

[dishdude]

Good video relevant to this thread.

 

[01rangerxl]

The size of these cars is crazy. As far as parking and such it probably wouldn't be much different from a Suburban.

 

[390pcode]

Here is my 1971 Biscayne BO7 Police package. 402/4bbl turbo 400, 3.42 posi. From Douglas, County, NV. I took this pic on the way back from SE Pennsylvania where I picked it up. GM never could crack the copcar market until the late 70's so, 60's and early '70's police package GM cars are extremely rare. The only reason our Sheriff's dept bought Chevys is because there was a small dealer in our little town. Brakes and fuel tank is done; I am rebuilding the motor now. I collect and restore police cars only.

 

[Number_35]

Here is my 1971 Biscayne BO7 Police package. 402/4bbl turbo 400, 3.42 posi. From Douglas, County, NV. I took this pic on the way back from SE Pennsylvania where I picked it up. GM never could crack the copcar market until the late 70's so, 60's and early '70's police package GM cars are extremely rare. The only reason our Sheriff's dept bought Chevys is because there was a small dealer in our little town. Brakes and fuel tank is done; I am rebuilding the motor now. I collect and restore police cars only.
View attachment 125914

Please keep us posted with your progress. It was very common for the plastic eggcrate grilles to have a bit missing like that, even back in the day.