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big block?

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big block? - 7/17/2007 10:20:14 PM

NickD

Posts: 18
Joined: 7/13/2007
Status: offline

When I was reading the facotry specs on my 1974 vette, it said (if I'm not mistaken) that it had installed a 350 Big Block. When I showed pictures to my friends (bragged) they told me that anything less than 400 CI was considered a small block? Who is correct? Am I wrong and the engine is indeed a 350 CI Small block?

Post #: 1

RE: big block? - 7/18/2007 2:45:45 AM

78buckshot

Posts: 654
Joined: 1/28/2007
From: Michigan
Status: offline

Hi Nick, factory small blocks were built with these c.i.'s, 265,283,302,305,307,327,350,400. The big blocks were 348,396,402,427,454. So you can see the displacement doesn't necessarily mean small or big block. In 1974 the factory offered the 350 or 454, send us a photo and we'll tell you what you have.

(in reply to NickD)

Post #: 2

RE: big block? - 7/18/2007 5:18:33 AM

C3 Starship

Posts: 4761
Joined: 7/25/2006
Status: offline

Actually, just look at the exhaust manifolds. If the 2 center ports are close together, it's a small block. If all 4 are evenly spaced, it's a big block.

_____________________________

1980 L-82 Fastback (forward too)
Mono composite front and rear.
Full adjust ride height and
response.
400+ hp, 454, M-22, 3.07

http://i121.photobucket.com/albums/o225/C3Starship/Patch.jpg

2007 H. D. Sportster, XL 883 EFI

(in reply to 78buckshot)

Post #: 3

RE: big block? - 7/18/2007 10:02:57 PM

Wedge

Posts: 227
Joined: 11/3/2005
Status: offline

Hey Nick,
Another way to find out what you have is by checking the casting numbers located on the block behind the driver side cylinder head. If you have a 3999289 cast number... big block. If it is a 3970010, it is a small block. Both of these numbers are actually cast in the mold, not stamped. Maybe this will help.
Later,
Wedge

(in reply to C3 Starship)

Post #: 4

RE: big block? - 7/18/2007 10:04:58 PM

NickD

Posts: 18
Joined: 7/13/2007
Status: offline

thanks for all of the tips

(in reply to Wedge)

Post #: 5

RE: big block? - 7/20/2007 8:04:54 PM

73shark

Posts: 1097
Joined: 4/18/2006
Status: offline

Another clue is that small blocks have four mounting hole valve covers and big blocks have more (7 or 8 I think).

_____________________________

So many toys, so little time

(in reply to NickD)

Post #: 6

RE: big block? - 7/20/2007 8:14:14 PM

C3 Starship

Posts: 4761
Joined: 7/25/2006
Status: offline

.....and the valvecovers are a lot wider, about oh,....6 inches or so. SB's valve covers are only about 4 inches wide.
So Nick, ya got it figured out?
Took me a while, before I caught on.

That was a long time ago now, but hey, we all had to learn some how.

(in reply to 73shark)

Post #: 7

RE: big block? - 7/21/2007 10:44:18 AM

NickD

Posts: 18
Joined: 7/13/2007
Status: offline

well, I still havent gone home yet to check but here is a picture-

http://www.corvetteforums.com/albumtn.aspx?size=mid&imgpath=5860-asppg_Pg330060684.jpg

(in reply to C3 Starship)

Post #: 8

RE: big block? - 7/21/2007 11:00:35 AM

C3 Starship

Posts: 4761
Joined: 7/25/2006
Status: offline

Nice ride! Looks very clean.

Just from the valve covers, I say Small Block. I can't see the exhaust mans, but ya, she's a Small Block.

Hurry home, she's gettin' lonely!

_____________________________

1980 L-82 Fastback (forward too)
Mono composite front and rear.
Full adjust ride height and
response.
400+ hp, 454, M-22, 3.07

http://i121.photobucket.com/albums/o225/C3Starship/Patch.jpg

2007 H. D. Sportster, XL 883 EFI

(in reply to NickD)

Post #: 9

RE: big block? - 7/21/2007 12:30:29 PM

78buckshot

Posts: 654
Joined: 1/28/2007
From: Michigan
Status: offline

I can't bring up the image on my computer but if Starship says it's a small block then it's a small block. Don't be ashamed in front of your friends, you can make magic from even the lowliest of small block Chevrolet's.

(in reply to C3 Starship)

Post #: 10