Found out something interesting..

[suzq044]

So, we're doing a rebuild on what we thought was the factory 283 v8 for PJ. We decide to finally run the numbers while its out of the truck. Seems that it is actually a 1975 400 small-block that someone put a 283 intake on. (I'm assuming the PO decided to keep an aftermarket intake and just threw on the 283 intake just to be able to drive it.

We don't have it all torn down yet, so we don't even know if its salvageable yet.

This is what we can't figure out. What was built in the Fremont plant in 1975?
Terry wants to know as much as possible about it.
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[Captainfab]

The numbers and suffix code on the front passenger side of the deck surface of the block will tell you as much as is available for that engine.

[suzq044]

Damn.. we've tried that, and there is zero info on the vehicle it went into in 1975. The CSB is pretty much skipped over on the sites we HAVE found with information. Which is why I had hoped one of you guys would know :\

[Captainfab]

If the block was cast in '75, depending on the month, it could have been installed in a '76 model car. Here is what I have found

http://www.nastyz28.com/gm-chevy-cod...s-suffix-3.php

[bruceman1968]

Is CSB your suffix code? If it is then there are 4 possibilities,
CSB 73 400 Impala
CSB 75 400 Chevelle
CSB 76 400 Marine
CSB 76 400 Chevelle

[chevyrestoguy]

Look on the back of the block at the part number. It should end in -509 or -817. The later 400s were almost always the -817 blocks. It's a 2-bolt main, but that's actually a good thing. Those engines got a bad rap years ago for no reason at all, usually from people that never owned one. A 400 is a great engine for a street machine. It's give you the torque of a small big-block with the size of a small block. I'm a huge fan of 400s.

I say build it! You'll like it, trust me.

[suzq044]

Originally Posted by Captainfab

If the block was cast in '75, depending on the month, it could have been installed in a '76 model car. Here is what I have found

http://www.nastyz28.com/gm-chevy-cod...s-suffix-3.php

The block was cast in July '74; the heads were cast in oct. '74, the engine was assembled in oct. 74. The partial vin, says '75 m/y from Fremont. We just wanted to know what vehicle that would be.

[protrash64]

FYI, 400's were put in many trucks, too. I see Blazers with them all the time. I got my original 400sb from a Caprice.

[suzq044]

So far, this thing is not too horrible, but we're noobs, so we don't know what to look for as far as 'damaged' stuff goes.. We only have the driver-side head off now; tomorrow we're probably gonna pull off the other.

We know it wasn't the original engine due to the fact it's a '75, and our truck is a '66, and according to the VIN was supposed to have a 283.. (the intake was all that was left of the 283, siliconed to death on top of the 400) but obviously, the 75 is a lil bigger at 400. LOL

We were curious to see, because we have a transmission we cant figure out (without pulling it out to check the numbers). We were kinda hoping the 400 and the trans were from the same 'donor' '75 vehicle; it's from a Car, that we know by the position of the shifter, and it's pattern; but otherwise, we'll have to drop it to figure it out "for sure".

[dugvera@gmail.com]

My 76 k10 came with a 400.

[DanSan c 10]

I like the 400, But others in my circle of trucks give them a bad rap. I will follow your progress to see what is up. Good luck.
From your neighbor down south. I have a 66 as well.

[dugvera@gmail.com]

I liked the 400. Good power. I did tow alot and the torque was good. When i lost the rod in it there was serious damage done to the block or id have rebuilt that one.

[dugvera@gmail.com]

Is that an old Ford 8n tractor all restored behind the camo burb?

[suzq044]

Originally Posted by dugvera@gmail.com

Is that an old Ford 8n tractor all restored behind the camo burb?

For a second I wasn't sure if you were talking to me, because PJ is a panel and that isn't our property. Its back where we bought it. Iirc, it was unrestored, and not in good condition.. the guy had like 5 old tractors on the property tho.
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[dugvera@gmail.com]

My bad. It a panel. I like those old tractors.
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[Notch1988]

You could always build a 377 out of the 400 block.

[1Bad62Pro/Street]

The (BEST) and (WORST) Small Block Chevys Engines Of All Time
http://67-72chevytrucks.com/vboard/s...d.php?t=386581

Small Block Chevy Engine Block Identification
http://67-72chevytrucks.com/vboard/s...d.php?t=353538

Growing to it's largest factory displacement of 400 cubic inches in 1970, these block required siamesed cylinders to gain the internal space for the displacement. Extra bolt holes were also drilled into the surface of each deck to promote cooling. It is also noted that for the use of a small block 400, you also need the small block 400 heads. Most of the crankshafts and connecting rods from the small block 400's ended up with a better life as part of a 383 build-up. The only 400 cubic inch size of this family, 400 cu in small-block, was introduced in 1970 and produced for 10 years. It was loosely based on the 'medium' journal 350 and had a 4.125-inch bore and a 3.75-inch stroke. The 400 differed from other small blocks in that the cylinders were cast siamesed, used a 2.65” 'large' main bearing journal, and oftentimes had one more core/freeze plug on both the left and right sides of the block. Initial output was 265 hp and was only available equipped with a 2-barrel carburetor. In 1974 a 4-barrel version of the 400 was introduced, while the 2-barrel version stopped production in 1975. 1976 was the last year that the 400 was used in full and mid-sized Chevrolet Passenger car, available in both A-Body and B-Body lines. While popular with circle-track racers and drag racers, the engine could be prone to cooling problems if cylinder heads without added steam holes were used. I'm not a fan of them myself. It's popular in drag racing around my neck of the woods.

Got one for sale though!
1970 Chevy 400 cu in SB, Casting 3951511 Canadian Block
http://67-72chevytrucks.com/vboard/s...d.php?t=408630

Casting CID Year Model Aplication Comments
330817 400 73-76 Passenger 2 bolt main,3 freeze plugs/side
330817 400 75-80 Truck 2 bolt main,3 freeze plugs/side
3951509 400 73-76 Passenger 2 bolt main, 2 freeze plugs/side
3951509 400 75-80 Truck 2 bolt main, 2 freeze plugs/side
3951511 400 70-73 Pass,Chevelle,Monte 4 bolt main, 3 freeze plugs/side
3951511 400 75-80 Truck 4 bolt main, 3 freeze plugs/side

[suzq044]

330817 400 73-76 Passenger 2 bolt main,3 freeze plugs/side
330817 400 75-80 Truck 2 bolt main,3 freeze plugs/side

^ our engine has 2 plugs and has this casting number.. o_O

franken motor.. dunnn. dunnn... dunnnnnnnnnn

[suzq044]

Also -- we're kinda stuck, terry doesn't want to order online, anybody have an alternative way of turning the crankshaft without the balancer on?

[doubleb's69]

I was told they got a bad rep because people would mess with them and put different heads on them and forget to drill the steam holes. They would over heat and so on so people call them junk. I had one and it ran great, never had a problem. Its just like the quadrajet. Everyone hates them but they are a great carb.

[gofastnut]

hey suzq044,
You're already gettin plenty of help on the engine side of things. Let's see if I can help on the trans side of things. Crawl under it w/ a pen and paper, or arm or hand. Draw the basic shape of the trans pan. TH350 will look like a square with one corner cut off. The TH400 will look kinda like Texas.
Hope this helps...

[dugvera@gmail.com]

Originally Posted by doubleb's69

I was told they got a bad rep because people would mess with them and put different heads on them and forget to drill the steam holes. They would over heat and so on so people call them junk. I had one and it ran great, never had a problem. Its just like the quadrajet. Everyone hates them but they are a great carb.

Yes! I have a quadrajet and hate it but not sure im ready to install the Holley yet.
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[gofastnut]

Thanks for the Pic, Pro Street. I agree with the 400 and Q-jet "bad rap" I've never had a problem with the 1 400 I had. I had problems with a stock Q-jet, but once I got it tuned up and in, it was great!

[Captainfab]

If you are talking about turning the crank with it still in the engine, a correctly sized crescent wrench will work just fine as long as the key is still in the crank.

Originally Posted by suzq044

Also -- we're kinda stuck, terry doesn't want to order online, anybody have an alternative way of turning the crankshaft without the balancer on?

[protrash64]

Originally Posted by suzq044

We were curious to see, because we have a transmission we cant figure out (without pulling it out to check the numbers). We were kinda hoping the 400 and the trans were from the same 'donor' '75 vehicle; it's from a Car, that we know by the position of the shifter, and it's pattern; but otherwise, we'll have to drop it to figure it out "for sure".

The trans that came with my 400sb was a TurboHydro375. It is a light duty T400 with a T350 tailshaft. It has fewer clutch pacs than a T400 but can be upgraded. Again, this came out of a Caprice.