BB or SB what the hell?

[Broken_down?]

I know this is going to get me flamed something feirce, but how does one tell the difference between a big block and small block other then the size? or is it based on size? I have 350. is that big or small?

flame away

broken_down?

PS. before you start flaming me.. remember this. " We all had to start by asking questions too..LOL"

[paintpyro]

broken down, your 350 is a small block. No flamin

[Broken_down?]

how do you tell the difference?

[paintpyro]

Personally, I usually notice in the size of the valve covers. As far as displacement is concerned (350,454,etc), I've just picked it up as Ive gone along. Someone here will be able to tell you better than I can.

[bpmcgee]

Well, side by side, the big block is definitely MUCH bigger.

If you don't have them side by side, check the valve covers. Small blocks have 4 bolt, symmetrical valve covers and big blocks have 5 bolt, asymmetrical valve covers.

Also, Chevy made specific displacements. 307, 350, 400 are all small block. 396, and anything OVER 400 are all big block. This gets confusing if you talk about oddball sizes that people make for themselves, but standard sizes were all like this.

After you stare at the engines for a while, it will be second nature.

Brian

[Broken_down?]

sweet thx for helping me out. apperiated.

---broken_down?

[shuttermutt]

Here's a quick reference I just threw together for what it's worth. I don't claim to be any kind of expert. I just grabbed an opportunity to give back to the board a little bit. I'm like paintpyro in that I usually notice the valve covers first.

Chevy Small Blocks
262 - 4.3l (2)(3)
265 - 4.3l (2)(3)
267 - 4.4l (2)(3)
283 - 4.6l
302 - 5.0l (1)
305 - 5.0l (2)
307 - 5.0l (2)
327 - 5.4l
350 - 5.7l
400 - 6.6l

Chevy Big Blocks
396 - 6.5l
402 - 6.6l
427 - 7.0l
454 - 7.4l
502 - 8.2l

Engines in bold are generally the most common and popular for build-ups. There's plenty of room for disagreement on that, though. Also, this list does not include many of the popular crank/bore combinations that engine builders like such as the 383 (350 block bored .030 over with a 400 crank and balancer).

(1) Rare 1967-69 Z/28 engine. Can be made with a 283 crank in a 327 block as I recall.
(2) Not terribly desirable, but can be built hella strong
(3) Oddball

I also just edited to include ACTUAL liter displacement. Funny how you don't realize just how much bigger those big blocks are until you see the liter numbers. Personally, however, I friggin hate liters as a displacement unit.

[bigjimzlll]

look at the headers...big block has 4 equally spaced tubes...a small block has the 2 center cylinders closer

[guitarornothin]

[FRENCHBLUE72]

No flamin here is a small block pic for you ... Just remember there are no dumb question's only those no asked I remember when I knew very little about automotive related thing's..

[Broken_down?]

frenchblue72: do yu have disc brakes on your truck?

[FRENCHBLUE72]

And here is my big block

[FRENCHBLUE72]

Yes I have disk brake's.. The first pic is my blazer and the 2nd pic is my 2wd these both are 72's.. I also have a 69 that I bolted a 72 disk brake clip onto very easy mod...

[Broken_down?]

so if you have a poerbooster you have discbrakes?

[FRENCHBLUE72]

Not alway's the case.. The power booster is just to supply vaccum assist to the brakeing effort.. You can have regular disk brake's with out the power assist.. Someone please correct me if I am wrong..

[Broken_down?]

hmm wish I had a pic of disc brakes. but thx for the info bud.

[FRENCHBLUE72]

What pic would you like to see???? Also there is a thread going right now on disk brake swapping ,lot's of good info for you to read if you are considering the swap..

[miket]

You know...not to get off topic, but this is a fine example of why this forum is so successful......if something like this (no offense) would have been posted on any other forum, I would have needed a kevlar suit and fire helmet just to log on.

Cool guys.....

[ROAD DOG]

Hey FrenchBlue,

that's the biggest air cleaner I've seen!!!! What is the dimensions

24" x 10" thick???

I said god damn.

[Tx Firefighter]

Frenchblue72- What are you going to use for exhaust on that big block? Looks like you have it sitting on 6 cylinder mounts. I've never been able to find any header or manifold that will work in that scenario.

[rage'nrat638]

HERES MY BIG BLOCK

[padreisla]

Well not as nice as rage'nrat638, but still its mine. Here is a pic of the 454 in my 67. We cleaned and painted the engine compartment and put all of the wires and hoses in tubes.

Thanks......Joey

[rage'nrat638]

Well not as nice as rage'nrat638, but still it mine

HEY THATS MY 85...
I JUST WISH MY 69 HAD A BIG BLOCK....

I JUST GOT A LITTLE 355

AND BY THE WAY YOURS LOOKS SWEET

[lukecp]

Originally posted by miket
You know...not to get off topic, but this is a fine example of why this forum is so successful......if something like this (no offense) would have been posted on any other forum, I would have needed a kevlar suit and fire helmet just to log on.

Cool guys.....

You ain't kidding Mike!!

You really appreciate this fourum when you log onto other car boards and see how everyone treats each other....everyone over here gets along just fine (besides the political BS forum, and it is even pretty civil)

Nothing wrong with basic questions.....no one was born with a knowlegde of Chevy motors

[Tx Firefighter]

Expanding on what bpmcgee said, I went out to the garage wall and snapped a couple of pics of the two. By the way, the big block has 7 bolts per cover, not 5.