Pontiac 400

[Goldie Driver]

i mean just from practicality, i say we should put buick small blocks in things because of oil pump and distributor. thats all she wrote.

Aren't all Buicks front distributor?

 

[HotRodPC]

Pontiac actually quit making the 400 in 78.

They stock piled like 9000 to use in 79, but they sold more than planned and I think there were 7900 put in Formulas and T/As in 79, and all were 4 speeds with no cruise.

403 has potential, but in stock form is just another smog motor.

400s are strong motors, or can be, but I prefer to see them in a Pontiac car.

My .02.

I was thinking it was actually 76 they quit making the Pontiac 400 and they stockpiled them for use in coming years with manual transmissions only. You're prolly right though. Olds quit the 455 and many GM engines quit like the Caddy 500 in 76. 77 was the first year for GM Engines and that's when all hell broke loose and GM got sued. For example, you get an Olds and get home to find out it just had a Chevy 305 in it.

 

[Matt69olds]

About the only parts that will interchange between a Pontiac and a Chevy is the distributor cap.

Pontiac 400 are pretty torque engines, especially with a little work done. Like all the smog engines of the era, they were all detuned with low compression, lazy camshafts, and restricted exhaust.

If you don’t have a engine for your truck, then it might be worth it do the swap. The Chevy trans won’t bolt to the Pontiac, but adapter plates are available. Engine mounts will need to fabricated, along with some wiring changes. I have no clue if the water pump/ thermostat outlets would be the same size, so same hoses or radiator work might be needed.

Unless you just want some Tin Indian power under the hood, it would be far easier to find a Chevy engine.

 

[AuroraGirl]

I was thinking it was actually 76 they quit making the Pontiac 400 and they stockpiled them for use in coming years with manual transmissions only. You're prolly right though. Olds quit the 455 and many GM engines quit like the Caddy 500 in 76. 77 was the first year for GM Engines and that's when all hell broke loose and GM got sued. For example, you get an Olds and get home to find out it just had a Chevy 305 in it.

my 77 electra has a buick engine, the main engine choice. the 78 electra however is where it saw chevrolet

 

[Ricko1966]

Ignore this, somehow I posted it here instead of where the guy was looking to hop up a 403.

A big block olds,as in 455. Bolts right in bolt for bolt nut for nut ,in place of a 403.,same mounts, same exhaust and if you don't tell anyone they won't know it's not a 403.Olds big blocks were really just stroked olds small blocks the decks a little taller to allow for the extra stroke.Its a 1 afternoon swap.Yep you can go Chevy easy,but not as easy, yep a buick will bolt in if you use pontiac mounts or you can go pontiac, but the simplest is Big Block Olds

 

[Matt69olds]

Did I miss where the OP had a Olds in his truck? If so, swapping a 455 in place of a 403 is about the easiest swap there is. All that is needed is longer fan belts, due to the 455 taller deck height. The 1/2 added deck height moves all the accessory center to center distances about 3/4 of a inch, meaning all the belts need to be about 1 1/2 to 2 inches longer. All the accessory mounting brackets will bolt up, the lower alternator bracket needs a small spacer installed between it and the power steering bracket. If the truck is equipped with A/C and has the R4compressor, the front A/C bracket needs the mounting tabs extended to reach the water pump. That’s it, that’s about the extent of modifications

 

[AuroraGirl]

Ignore this, somehow I posted it here instead of where the guy was looking to hop up a 403.

A big block olds,as in 455. Bolts right in bolt for bolt nut for nut ,in place of a 403.,same mounts, same exhaust and if you don't tell anyone they won't know it's not a 403.Olds big blocks were really just stroked olds small blocks the decks a little taller to allow for the extra stroke.Its a 1 afternoon swap.Yep you can go Chevy easy,but not as easy, yep a buick will bolt in if you use pontiac mounts or you can go pontiac, but the simplest is Big Block Olds

whats this about buicks bolting in? you mean in place of stock pontiac?

 

[AuroraGirl]

Did I miss where the OP had a Olds in his truck? If so, swapping a 455 in place of a 403 is about the easiest swap there is. All that is needed is longer fan belts, due to the 455 taller deck height. The 1/2 added deck height moves all the accessory center to center distances about 3/4 of a inch, meaning all the belts need to be about 1 1/2 to 2 inches longer. All the accessory mounting brackets will bolt up, the lower alternator bracket needs a small spacer installed between it and the power steering bracket. If the truck is equipped with A/C and has the R4compressor, the front A/C bracket needs the mounting tabs extended to reach the water pump. That’s it, that’s about the extent of modifications

I gotta super secret stock... 455... its a real sleeper, so you wouldnt think its a 455 but the deck height and manifold setup are misleading, it may look like a 260 but i promise its a real screacher.

I can prove it, the cutlass isnt a supreme, its an XTREME. super rare, super secret trim level!

Yours today for 5000, no test drives.

 

[Ricko1966]

whats this about buicks bolting in? you mean in place of stock pontiac?

I bought a 1975 Transam previous owner put a 455 buick in it. I pulled the buick engine, and dropped a poncho with a ram air cam and headers right back down.Didnt touch the frame mounts just pulled the Buick , set the pontiac down on stock mounts didn't have to move anything, as in transmission cross member.

 

[HotRodPC]

Ignore this, somehow I posted it here instead of where the guy was looking to hop up a 403.

A big block olds,as in 455. Bolts right in bolt for bolt nut for nut ,in place of a 403.,same mounts, same exhaust and if you don't tell anyone they won't know it's not a 403.Olds big blocks were really just stroked olds small blocks the decks a little taller to allow for the extra stroke.Its a 1 afternoon swap.Yep you can go Chevy easy,but not as easy, yep a buick will bolt in if you use pontiac mounts or you can go pontiac, but the simplest is Big Block Olds

Yep, Pretty much my explanation of a Big Block Olds is a Tall Deck Small Block. Small Block heads even bolt on Big Block and Vice Versa. Though I don't recommend that. Compression gets to high on a Big Block and to low on a Small Block but they will bolt up.

 

[AuroraGirl]

Yep, Pretty much my explanation of a Big Block Olds is a Tall Deck Small Block. Small Block heads even bolt on Big Block and Vice Versa. Though I don't recommend that. Compression gets to high on a Big Block and to low on a Small Block but they will bolt up.

Similar to pontiac, yes? IIRC the external dimensions dont change much from 400 to 455 but from smaller CI to 400 there is some, but because of heads? So externally, a 455 and 400 would be the "same" other than motor mounts being beefier after a certain year and likely not seeing many 2 barrel on 455
buick i think does have a difference

 

[HotRodPC]

Similar to pontiac, yes? IIRC the external dimensions dont change much from 400 to 455 but from smaller CI to 400 there is some, but because of heads? So externally, a 455 and 400 would be the "same" other than motor mounts being beefier after a certain year and likely not seeing many 2 barrel on 455
buick i think does have a difference

Pontiac none of the dimension changed in v8 as far as cubes from 326 all the way up. There is no small block or big block, it's a v8 block.
Or some referred to them as old block or new block. I think it was 67 was the end of 389 and 421 and it went to a new generation of blocks of 326 to 350, 389 to 400 and 421 to 455. But each gen the block dimensions were all the same regardless of cubes.

 

[AuroraGirl]

Pontiac none of the dimension changed in v8 as far as cubes from 326 all the way up. There is no small block or big block, it's a v8 block.
Or some referred to them as old block or new block. I think it was 67 was the end of 389 and 421 and it went to a new generation of blocks of 326 to 350, 389 to 400 and 421 to 455. But each gen the block dimensions were all the same regardless of cubes.

its what i figured. i wish i had the 455 tho. stupid 2 barrel smog 400 ;( but it does have th400