400 Chevrolet with 305 Heads

Hi

I am a Wild West German so Sorry about my English.

No here is my Question. I have a 84 G20 Van with a 305 Engine for daily driving. The Engine is in bad Condition and now I rebuild a 400 Small Block from a 69 El Camino. The Engine is ready now with new bearings, Piston Rings, High Volume Oil pump and Edelbrock Performer Cam.
I would like to use the 305 Heads on the 400 Engine. Is that possible or is it to much pleasure?

I will use a 600 Ede Carburettor , Performer Manifold, and Headers with a dual Exhaust .

THX

its not worth it you wouldnt be able to use pump gas with that much compression and it would be alot of work.....im not familar with big blocks but i know you cant match a cylinder head with that small of valves and small combustion chambers dont do it just get some different heads

you as autocityman4 has said, the compression would probably be 11- 12/ 1 compression and the rule of thumb max for running pump gas is about 10/1 compression, therefor, you would ither need to use just a little laquer thinner in the gas ( toulene and xylene, main ingrediants, big octane booster, ingrediants used in most off the shelf octane boosters ) but I wouldn't recomend that, think of it this way, the 305 heads you have, will raise the compression and lower the performance because of the port size diffrences, you could buy a new set of Vortech heads from any GM dealership, for around 600 a set, or if performance isn't a problem, any 350 head would work fine, some might limit performance like a stock 80's caprice or somthing set of heads but, a set of 461 heads would be nice.

305 heads on a 400, way too much static compression ratio for pump gas. Plus, you'd have to drill the 305 heads for steam holes. Do you have the 400 heads?

but tech, whats wrong with 12:5-1 :HMMM: ......................:LOL:

At first thx at all

It is a 400 er Small Block no Big Block.
Yes I have the Original Heads .But I read that Chevy Heads before 1974 are not so good.
I can get some used old Heads from a 350 for a low Price.
Some Power in my Engine will be fine but the important thing is to drive it every Day without Problems. Gas is very Expansive (like everything in Germany) and it will be fine to ride with low Octane

Quote:

---

Originally posted by gassersrule_196
but tech, whats wrong with 12:5-1 :HMMM: ......................:LOL:

---

12.5 is fine on a 283, Scooter :LOL: :LOL: :LOL: :LOL:

Quote:

---

Originally posted by outlawz
At first thx at all

It is a 400 er Small Block no Big Block.
Yes I have the Original Heads .But I read that Chevy Heads before 1974 are not so good.
I can get some used old Heads from a 350 for a low Price.
Some Power in my Engine will be fine but the important thing is to drive it every Day without Problems. Gas is very Expansive (like everything in Germany) and it will be fine to ride with low Octane

---

Unless someone has added them since the 1969 400 heads were produced at the factory, they will not have hard valve seats to contend with the unleaded fuels which are available today at the gas pumps in America. I don't know if you can get leaded fuel where you are.

1973 and later heads will have induction hardened seats and will be compatible with unleaded fuels unless multiple valve jobs have been performed on the heads, thus cutting through the hard material.

The 400 heads which you have can be upgraded by having them machined and hard seats installed, or you can use 1973-up 350 heads with 76 cc combustion chambers and have the same thing, except that the 350 heads must have steam holes drilled in them in order to be compatible with the 400 block. (use a 400 head gasket as a pattern).

the 305 heads will give added compresiion yes, so much so, that to be able to use them, youll have to use dished pistons to run pump gas, + the 305 heads dont flow ...although on a van Im gonna assume thats not a big issue.
I think I use World Products s/r heads for that application...whatever heads you choose...make sure to add steam holes to the heads for compadibility with the 400.

We don’t have leaded Gas anymore. So what I hear is that I better take a look for the 350 Heads with the right Holes inside. That will doing a good Job and I probably can run with low Octane. The Power from this little Engine will be enough for a daily driver.
We have only a normal timing point lamp. In my books I can find many different settings fore this Engine. Is it ok to set it on 8 degree?

Regards

Andy

un-leaded fuel can you say parts washing material:LOL: :LOL: :LOL:

HEHE you are soo right.
Be Happy that you live on the other Side of the Orange
Over here its real hard if you like old Cars with real Engines

"Is it ok to set it on 8 degree?"

Yes. Once you have the motor running, it will tell you where it wants the timing to be. It's called "timing by ear". Keep turning the distributor a little at a time in the advance position (counter-clockwise) and lugging the motor down by going uphill or stalling it against the foot brake until the motor spark knocks, then retard the distributor position a little (clockwise) until you have no knock. Lock the distributor down there and enjoy.

Techinspector I think you play a long time with Chevy V8s and know a lot about those Engines. Thank you and all the others. It was very helpful for me.
Maybe I will found the time to complete the Engine this Week . Than I let you know how it works.
I have found a great and interesting website.

Best regards to all and bye for now

Andy

You're welcome Andy, now be sure and pay attention to the steam holes you must drill in the heads if using heads other than the 400 units. The 400 block is siamezed (water does not flow between the center cylinders), so steam pockets develop that must be relieved through these steam holes into the heads.

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.:mad:

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.