Thread: 400 Chevrolet with 305 Heads

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Somebody has mis-informed you...

Go here http://www.carcraft.com/techarticles/1001/ and click on the picture to the right that states, "400 quick data."

400 SMALL BLOCKS were not produced until 1970, and no HI Perf 400 motors were ever produced.

I just rebuilt mine; Small Block 400 in a 72 El Camino, but this is not the stock motor, and El Caminos didn't get 400CI motors until 1974.

I've done extensive research, and there are some danger points you should worry about. 400 small blocks are externally balanced motors so flywheel and Harmonic Balancer are the balance points, don't re-use the 305 parts here, or the motor will shake itself to death.

Can you provide the block number? It should be on the LR of the motor on the same plane as the cylinder head. For instance my number is 3951509 and is stamped in roughly 1 cm tall numbers. Another number that will exist if the block has not been decked, will be on the RF head surface at the extreme front of the motor.

Best regards,
Andy

20 Year Professional Master BMW Motorrad and Auto technician,
Now Microsoft employee, with a hotrod hobby. :-)

Sorry that I didn't answer such a long time but there was a lot of work for me in the last weeks.

Aim not a rich Man so I have to do it HEHE

Ok Yesterday I take a look at my Engine and see the difference between the 350 and 400 Waterholes. After that I take of all the Valves from the 400 Head. I will give them to somebody who can plan the Head and fit the Valves back in.
But before I do that I will give you the numbers that I found on My Engine and Heads.

Engine at the back 330817.

At the front 14B459345 / TI030CTA

Head GM7T / J4 73 / 333882

Whatever that means.

I hope that I can use them with unleaded Gas

Thank you Guys

Regards

Andy

I take a look at the page and see that the 2 Bolt is build in 73.

So on the Head i can see J4 73.

Probably the Engine is a 73 and not a 69

right ???

Engine at the back 330817.

At the front 14B459345 / TI030CTA

Head GM7T / J4 73 / 333882

Whatever that means.

I hope that I can use them with unleaded Gas

Block:
330817 SB400 72-80 2bolt mains.

Heads:
333882 74-80 350/400 75cc chambers 1.94 / 1.50 valves, should have the hardened seats already, unleaded should be no problem.

These heads will work well for a street motor, but are not so good to have port work done. (I use the same casting number).

Taking the two numbers and the date ranges indicate this motor should be at least a 74. Heads were cast in 73, the whole motor was probably in a station wagon, light truck or full size car.

But you gave more info that confirms it.
The CTO suffix code, (the last 3 in the front block numbers). show this motor was:

Built in 1974
Suffix code of CTA
SB 400
Automatic transmission
Vin code U
Engine name LT4
HP 175
2 Bolt mains
Bodies used in "A" "B"

Cheers,
Andy

Hi again and thx you all

I am really busy the last weeks and there is no time for my Engine. The Heads are Ready now , clean Valves and Plan ? ( dont know the word ) Heads

In the Next weeks I have to make a Move, we rent a litle Farm in another Side of Germany. This will give me a lot of work 2. But the Day will come for my Chevy.

Now I have another Problem. A Friend of mine drives a Dodge Ram Van from 89. Somebody kill the litle Window on the Driver Side.
Its not easy to get this one in Germany.
If somebody can give me a Window like that, please let me now the Price inklusive the overship to Germany.

Thx a lot

Regards
Andy

it shouldnt be that exspenssive to get one cut if its flat

Bought this sweet 73Nova "SS" with 400SB---lasted 3,000 miles and this is what has happened---"400 small blocks are externally balanced motors so flywheel and Harmonic Balancer are the balance points, don't re-use the 305 parts here, or the motor will shake itself to death."

Joined this forum because I found the info here that explained why a well built engine with low miles suddenly lost oil pressure and developed a TERRIBLE vibration beginning about 4,000 RPM.
And knocks like a rattle snake when it is idling.

The engine was built and in the car when I bought it 7 June 2005---today is 4 August 2005 and I am exploring remedies...including a complete rebuild or replacement with a remanufactured engine (still the 400SB...it just runs to well!!!

Any input is appreciated.

Wow !!! Thats a hard 1.

I have so much work to do and the Engine is still in the Garage. The Heads are ready now ( nice and clean ) But no Time.
Maybe its good that i didnt found the Time. I have the Original Balancer and wanted to use it anyway. But no Idea what I have done with the Flywheel.
I remember that the Flywheell dosent fit the Converter of my TH400.
Is the Flywhell so importand?

i like the old Nova, its a real nice car.

Regards

Andy





q

it is very important that you use a 400 flywheel and harmonic balancer. that is the only way the engine is balanced. with out the 400 pieces the engine will shake to death. i have ran the same 400 in my camaro for 14 years, very hard, and it is still together. any other questions just ask . i will try to help.

73 Nova SS---your crankshaft could be broken, or a main web failed.