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CHEVROLET Small Block 400


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ENGINE, CHEVROLET Small Block 400, can hear run. $500

 

 

I saw this in the paper. Should I get it? Will it mate to the camaro t5? What are the advantages and or disadvantages to the 400 over the 350? I know some of you have had a 400, but I couldn't find anything when I searched. I;ll keep looking.

 

Jake

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I love a 400 small block. Torque of a bigblock and rpm of a small. Just have to make sure your cooling system is primo.. Take a 400 and put some corvette aluminum heads on it with a nice cam and you got a low buck Vette threat!! All smallblock goodies bolt on, same bellhousing, distributor etc. And if your lucky its a truck motor so you get 4 bolt mains...

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SBC 400 is a good motor, we have a couple. Actually the 2 bolt main is stronger than the 4 bolt, and if you have a 2 bolt main then you can always add splayed caps.

 

It sounds like a good deal if it is the oringinal 400, then when and if you rebuild it, it would probably need to be bored 30 over - thus a 406.

 

I turn mine to 6500 rpm with no issues, I have stock rods and crank in that engine. Of course I do have good heads, roller cam, etc.

 

Around here generly a good 400 block will run you about $400.00, this is used, no machine work etc. They are getting to be a rare breed.

 

John

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The 4 bolt block has 3 freeze plugs on the side, easy way to tell if it's a 4 bolt. I have two 4 bolt 400's, here the 4 bolts go for $600. Like JNJ, I turn em up to 6500 to 7000, never had a problem. In dirt track we run cast cranks, I won't go for stock rods, although I have in my early days, upgrade to a set of 350 rods, clearance them for the cam, and buy corresponding KB hyper pistons, add ARP bolts and you'll be pretty good. For low buck the Dart platinum series heads work well and in a z it's hard to overcam a 400. Isky makes a great hydraulic, 236 duration and .510 lift on a 108 lobe center, works really well with dart heads, victor jr, headers, 750 holley.

 

In my 3800lb monte before I pimped it, I went 12.58 with a 9:1 compression 400 with that cam, Dart II's, 1.6:1 roller rockers, 4.11's, slicks, th400, 3500 TCI stall, and a quadrajet on pump gas! And we are at altitude! I've got video still, crazy, my first drag race days!

 

Isky makes another that is 232 duration at .050 and .485 lift if you want alittle milder.

 

Ditch the stock harmonic, they are prone to cracking at the keyway at high rpm's due to the counterweight cutout, find you a used fluidampr, accept no imitations! And buy a SFI rated flexplate for $65 and don't skimp there either.

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just some info, not ALL 400 blocks have three freeze plugs per side and not ALL blocks with three freeze plugs are 4 bolt blocks there ARE frequent exceptions

 

3951509....400...70-71...4

3951509....400...74-80...2

3951511....400...70-73...4...Some replacement blocks had 2-bolt main caps

 

youll need to drill steam holes in heads not orriginally mated to the factory 400 block if you run on the street, you can use the head gaskets as a partial guide

 

Steam holes are recommended for all 400 block applications. Use a 400

gasket as a template and drill the three holes nearest the spark plug side of the head straight down, the other three which are very near the head bolt holes should be drilled at a 30 degree angle away from the bolt hole. The center hole will intersect water about 1" down and the two outboard holes to a depth of 2 1/4". Use a 1/8 drill.

 

http://www.gregsengine.com/350to400.htm

 

http://john.patblair.com/2c42o2.html

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I have run 3, 400-s so far.

It would really help me to better answer your question if I knew what the intended purpose is, for example what HP, my 400 SBC is nearly all aftermarket, the only remaining mass produced part is the block, and even that is modified, what I call build plateaus, meaning if you going to 300 hp, 400 hp 500 hp etc…this can make a big difference in the decision process defining the terms & conditions of operation.

They do pull more like a big block, but I don’t consider them as screamers like the 283-s & 302-s, your taste and preference will play a big part here,

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