402 BBC

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Frankinmetz

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Just bought a 402 big block with the original heads. I'm thinking about leaving the bottom end all stock and only doing performance parts on the top end. I've seen where guys get almost 550 horse from just doing that. Anybody else here put a 402 big block in their C10? Wanting to turn this into a daily driver with a little bit of kick behind it.
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BillK

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If the rest of the block looks as bad as what is in your picture I would not waste another second on it. Looks like it has been sitting in the ocean for a few years :( Your machine shop could tell you for sure but thats my opinion going by the one picture.
 

Frankinmetz

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It's been stored in a lean-to-barn for about 4 years, so most of that's just surface rust. I am taking it to a local machine shop to have it magnafluxed and also have the cylinder walls checked out before I start doing anything to it.

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Alaska 79 K-10

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Should be a fun build. Oval port heads, dual plane intake, 9.5 compression, headers, and a healthy hydraulic flat tappet cam. Sexy and affordable. Would recommend ARP rod bolt when you get the connecting rods resized. Grrrr
 

shiftpro

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Groove the lifter bores.
 

Raider L

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A good acid dip will get all that rust off of it. What year block and heads are they? I like those motors.
I've read that GM called this engine a 396 for insurance purposes because an engine of 400 cubes was considered a big block and to much power or some such bs. What was the story?
 

Frankinmetz

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A good acid dip will get all that rust off of it. What year block and heads are they? I like those motors.
I've read that GM called this engine a 396 for insurance purposes because an engine of 400 cubes was considered a big block and to much power or some such bs. What was the story?
Yeah I saw a thing where people use muriatic acid to clean it up. The head's and the block are both from a 1970 passenger car so I'm assuming a Camaro or Nova maybe possibly a corvair?

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bucket

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A good acid dip will get all that rust off of it. What year block and heads are they? I like those motors.
I've read that GM called this engine a 396 for insurance purposes because an engine of 400 cubes was considered a big block and to much power or some such bs. What was the story?

Probably just marketing. Very late in '69, they started overboring the 396, which made it a 402. Then for the '70 model year, they called it a "400" in all models except for the "SS 396" versions of Camaro and Chevelle.

Why in the hell they called it a '400' instead of a 402 is probably anyone's guess. Especially since for '70, there was the small block '400' which actually was a 400. The original factory literature I have calls the small block a "regular fuel 400" and the big block is called a "premium fuel 400".
 

Turbo4whl

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Yeah I saw a thing where people use muriatic acid to clean it up. The head's and the block are both from a 1970 passenger car so I'm assuming a Camaro or Nova maybe possibly a corvair?

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The 402 would have been a passenger car. Mostly full size, like an Impala or Biscayne. You would need an extremely big shoehorn to stuff a 402 in a Corvair.
 

bucket

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The 402 would have been a passenger car. Mostly full size, like an Impala or Biscayne. You would need an extremely big shoehorn to stuff a 402 in a Corvair.

'70-'72 trucks as well.


Big block Corvairs are out there, but I've not seen one yet that still had a back seat, lol.
 

Turbo4whl

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'70-'72 trucks as well.


Big block Corvairs are out there, but I've not seen one yet that still had a back seat, lol.

That't why you need the big shoehorn!
 

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