Stupid Question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Low Truck FNG · 05-21-2003, 11:14 AM

Okay, here's a stupid question by the newbie. The majority of my wrench turning growing up was on VW engines. What's the difference between a small block and a big block? Quit laughing and just answer!

78SilveradoSWB · 05-21-2003, 11:41 AM

About 100 cubic inches..

bigblock73 · 05-21-2003, 11:42 AM

Do you mean short block and long block? A short block is block without heads or intake...a long block is a complete block WITH heads and intake.

-Jeff

Prerunner1982 · 05-21-2003, 12:06 PM

small block 302-400 big block 396-502+ yes they over lap, you can tell the difference by looking at the engines, the big blocks have noticably larger vavle covers/heads.. as well as the block itself. a small block though a v8 looks small in 73-87 engine compartments.

bigblock73 · 05-21-2003, 12:12 PM

Oh sure, you edited it on me.

Anyways...what Jon said.

**Captkaos** · 05-21-2003, 02:02 PM

Hmmm, from memory...
BBC specs
typical bore size 4.25 max is 4.310"
4.84" bore spacing
9.80" deck height

SBC specs
typical bore size 4.00" max 4.150"
4.40" bore spacing
9.025" deck height.

bpmcgee · 05-21-2003, 02:09 PM

These guys have done a good job on the technical details. Let me give you the mono-brow perspective:

Small block V8s and big block V8s are different designs of engines. As such, their internal components aren't generally interchangeable. Accessories such as alternators, carbs, distributors, can generally be swapped with a like-type from the other engine, but not much else.

Internal parts within a design are generally inter-usable, but you have to be careful with the 400 SBC, because of the siamesed bores and altered water passages.

Brian

Low Truck FNG · 05-21-2003, 03:00 PM

Yes Jeff, I did edit the long block to big block. It just didn't look right after I re-read it. I knew the short and long difference. Thanks for the info guys. That clears it up.

jimfulco · 05-22-2003, 05:21 AM

You can't pick either of them up like you can a bug motor. Or build one on the kitchen table.

05-21-2003, 11:14 AM	#1
Low Truck FNG Registered User Join Date: May 2003 Location: Chandler, AZ Posts: 51	Stupid Question Okay, here's a stupid question by the newbie. The majority of my wrench turning growing up was on VW engines. What's the difference between a small block and a big block? Quit laughing and just answer! __________________ Brian '86 C10 Silverado, 350/700 Last edited by Low Truck FNG; 05-21-2003 at 11:29 AM.

05-21-2003, 11:41 AM	#2
78SilveradoSWB Senior Member Join Date: Apr 2002 Location: Beaverton, OR Posts: 1,615	About 100 cubic inches.. __________________ Mitch 1978 Chevrolet Silverado C 10 454 BB, TH400

05-21-2003, 12:06 PM	#4
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,904	small block 302-400 big block 396-502+ yes they over lap, you can tell the difference by looking at the engines, the big blocks have noticably larger vavle covers/heads.. as well as the block itself. a small block though a v8 looks small in 73-87 engine compartments. __________________ Jon 1982 Chevy Silverado 350/th350.... RETIRED 1993 Jeep XJ 2 door(Cherokee) 4wd 4.0ltr/AX-15 (5spd)/NP231 .... Oklahoma Roll Call

05-21-2003, 02:02 PM	#6
Captkaos www.73-87chevytrucks.com Join Date: Dec 1999 Location: Birmingham, AL Posts: 6,935	Hmmm, from memory... BBC specs typical bore size 4.25 max is 4.310" 4.84" bore spacing 9.80" deck height SBC specs typical bore size 4.00" max 4.150" 4.40" bore spacing 9.025" deck height. __________________ Chris Lucas 1973 Chevy C-10 1978 GMC Jimmy (2WD) - SOLD 1987 R10 twin turbo LS 1991 R3500 SRW CrewCab 1985 K5 diesel swapped project 1989 K5 2WD conversion w/ Vette susp Project Captkaos Customs 73-87chevytrucks.com

05-21-2003, 03:00 PM	#8
Low Truck FNG Registered User Join Date: May 2003 Location: Chandler, AZ Posts: 51	Yes Jeff, I did edit the long block to big block. It just didn't look right after I re-read it. I knew the short and long difference. Thanks for the info guys. That clears it up. __________________ Brian '86 C10 Silverado, 350/700

05-21-2003, 11:42 AM	#3
bigblock73 yeller Join Date: Oct 2001 Location: Twin Cities Posts: 13,824	Do you mean short block and long block? A short block is block without heads or intake...a long block is a complete block WITH heads and intake. -Jeff

05-21-2003, 12:12 PM	#5
bigblock73 yeller Join Date: Oct 2001 Location: Twin Cities Posts: 13,824	Oh sure, you edited it on me. Anyways...what Jon said.

05-21-2003, 02:09 PM	#7
bpmcgee Registered User Join Date: Mar 2003 Location: Northern Illinois Posts: 2,181	These guys have done a good job on the technical details. Let me give you the mono-brow perspective: Small block V8s and big block V8s are different designs of engines. As such, their internal components aren't generally interchangeable. Accessories such as alternators, carbs, distributors, can generally be swapped with a like-type from the other engine, but not much else. Internal parts within a design are generally inter-usable, but you have to be careful with the 400 SBC, because of the siamesed bores and altered water passages. Brian

05-22-2003, 05:21 AM	#9
jimfulco Registered User Join Date: May 2003 Location: Shreveport LA Posts: 3,170	You can't pick either of them up like you can a bug motor. Or build one on the kitchen table.



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