is this a true 4 bolt block? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

vtwinsport · 11-27-2010, 02:01 PM

Hey all,
is this a true 4 bolt block?

texasfunk · 11-27-2010, 02:08 PM

From the looks of it..looks like 4-bolt mains to me!

Posted via Mobile Device

vtwinsport · 11-27-2010, 02:21 PM

I thought the end caps had to be 4 bolt as well?

1BadSS · 11-27-2010, 02:29 PM

No

texasfunk · 11-27-2010, 02:31 PM

Quote:

Originally Posted by 1BadSS

No

Agreed
Posted via Mobile Device

cableguy0 · 11-27-2010, 02:31 PM

theres no room for the extra bolts on the end caps.Definately a 4 bolt

1BadSS · 11-27-2010, 02:43 PM

Quote:

Originally Posted by texasfunk

Agreed
Posted via Mobile Device

It's a factory 4 bolt motor. No one would really go through the trouble to drill and tap extra holes when 4 bolt blocks are so plentiful. Front and rear caps on 4 bolt motors never had 4 bolts in them due to space constraints like previously mentioned.

TheWhiteElephant · 11-27-2010, 03:52 PM

Quote:

Originally Posted by 1BadSS

It's a factory 4 bolt motor. No one would really go through the trouble to drill and tap extra holes when 4 bolt blocks are so plentiful. Front and rear caps on 4 bolt motors never had 4 bolts in them due to space constraints like previously mentioned.

http://www.dvorakmachine.com/4boltconversion.shtml

http://cgi.ebay.com/ebaymotors/ws/eB...d=170568672171

1BadSS · 11-27-2010, 04:41 PM

Quote:

Originally Posted by TheWhiteElephant

http://www.dvorakmachine.com/4boltconversion.shtml

http://cgi.ebay.com/ebaymotors/ws/eB...d=170568672171

Still cheaper and smarter to buy a used 350 4bolt block.

LONGHAIR · 11-27-2010, 05:14 PM

Quote:

Originally Posted by 1BadSS

Still cheaper and smarter to buy a used 350 4bolt block.

I think what he was getting at was "people do convert them"

80SPORT · 11-27-2010, 11:09 PM

The big block motors with 4 bolt mains are 4 bolt on all caps.....this may be why the was some doubt about the small block 4 bolt units only using 2 bolts on the end caps...

TheWhiteElephant · 11-28-2010, 09:40 PM

Quote:

Originally Posted by LONGHAIR

I think what he was getting at was "people do convert them"

Yes, thanks. If one is starting from scratch, sure the route to take would be to find a good, strong bottom end. The reasoning behind these conversions is that some folks may already have a solid foundation/built engine that it would be cost effective to get the kit.

I do believe though, that 2 bolt blocks are severely underrated by most. You have to be running some pretty serious power to "upgrade" to a 4 bolt block.

cableguy0 · 11-29-2010, 02:15 AM

Most of the 2 bolt vs 4 bolt argument is just hype. I would bet a punch in the gut that nobody can show one example of a block that failed because of the block in a street engine. IM talking anything under 1.5hp per cubic inch. Im not talking about thrown together junk that was severely out of balance and broke a main cap but actual block failure.

1BadSS · 11-29-2010, 02:50 AM

Quote:

Originally Posted by cableguy0

Most of the 2 bolt vs 4 bolt argument is just hype. I would bet a punch in the gut that nobody can show one example of a block that failed because of the block in a street engine. IM talking anything under 1.5hp per cubic inch. Im not talking about thrown together junk that was severely out of balance and broke a main cap but actual block failure.

I've had the main caps fracture on a 355 with only a tiny 175shot. Was caused by poor clamping force by the two factory main cap bolts. I used to have your thought process.

**Captkaos** · 11-30-2010, 04:17 PM

Factory 4bolt mains are weaker than 2 bolt mains. We used to drag race a lot and I have broken more 4 bolts blocks than I care to mention. Ask any reputable race shop and they will tell you 2 bolts always hold up better, 4 bolts weaken the block webbing.

If you want a strong block for the street a 2 bolt will do fine. If you have a 4 bolt use it. If you want ultimate strength get a 2 bolt block and have the mains machined for splayed caps.

http://www.jegs.com/i/Eagle/356/C4102S/10002/-1

spudz · 11-30-2010, 04:25 PM

Quote:

Originally Posted by Captkaos

Factory 4bolt mains are weaker than 2 bolt mains. We used to drag race a lot and I have broken more 4 bolts blocks than I care to mention. Ask any reputable race shop and they will tell you 2 bolts always hold up better, 4 bolts weaken the block webbing.

If you want a strong block for the street a 2 bolt will do fine. If you have a 4 bolt use it. If you want ultimate strength get a 2 bolt block and have the mains machined for splayed caps.

http://www.jegs.com/i/Eagle/356/C4102S/10002/-1

what he said..........

silvereagle07 · 11-30-2010, 06:40 PM

What's the casting number on the block?

BigBlocksRule · 12-01-2010, 08:45 AM

CaptKaos, how many 2-bolt blocks did you blow up drag racing? Chances are that you actually built a lot more 4-bolt blocks than 2.
Just messin' with you

The width of the cap where it mates to the block is the most critical area. A 2-bolt 400 is more like a big block with wide cap bases and registers, they'll take a lot more abuse because of this configuration.
I do agree, though, a 2-bolt block converted splayed mains is the best we can do short of an aftermarket block.
Second best is an early block with "2482" cast into the 4-bolt caps, they're nodular rather than grey iron, much stronger.

**Captkaos** · 12-02-2010, 06:36 PM

Quote:

Originally Posted by BigBlocksRule

CaptKaos, how many 2-bolt blocks did you blow up drag racing? Chances are that you actually built a lot more 4-bolt blocks than 2.
Just messin' with you

LOL, well after popping a few and having 2-bolts that were identical stay together we caught on quick and stopped putting money into them, my buddies stuck with the, but I swapped over to BBC's.

OlMech · 12-02-2010, 06:50 PM

Quote:

Originally Posted by Captkaos

LOL, well after popping a few and having 2-bolts that were identical stay together we caught on quick and stopped putting money into them, my buddies stuck with the, but I swapped over to BBC's.

4 Bolt blocks ARE stronger as far as the clamping force and stability. If you blew a 4 bolt apart, then you would have blown a 2 bolt with the exception being casting flaws.
factory cast blocks DO have flaws and weaknesses. When i have blown a 2 bolt block apart its usually been the caps that gave, the 4 bolts gave at the web. The Splayed main caps "help" the situation by leaving more meat where its needed. I have two two bolts on stands right now, both with blown main caps... in all honesty.. those of us blowing two or four bolt blocks should have learned long ago not to be so cheap and buy a stronger aftermarket block.....

TheWhiteElephant · 12-02-2010, 10:47 PM

Quote:

Originally Posted by OlMech

in all honesty.. those of us blowing two or four bolt blocks should have learned long ago not to be so cheap and buy a stronger aftermarket block.....

Or get a big block instead.

vtwinsport · 12-07-2010, 10:24 AM

Quote:

Originally Posted by silvereagle07

What's the casting number on the block?

I'll find it and post it.

allengator · 12-07-2010, 03:50 PM

Add me to the "Nothing wrong with a 2 bolt" club...
For a normally aspirated street engine, there are tons of other stuff to break first

rayfinseats · 12-08-2010, 02:55 AM

Most of the 2 bolt vs 4 bolt argument is just hype. Agreed. Probably an 010 block.

11-27-2010, 02:01 PM	#1
vtwinsport Registered User Join Date: Nov 2008 Location: edmonton, alberta Posts: 293	is this a true 4 bolt block? Hey all, is this a true 4 bolt block? Attached Images __________________ 76 Silverado, 2wd, long box, 350/th350, 3.42 posi, edelbrock performer 64cc heads, edelbrock 1405, 2101 intake, Hedman Headers, Comp Cam XE262 http://beerbreadbike.wordpress.com/

11-27-2010, 02:08 PM	#2
texasfunk Registered User Join Date: Jun 2009 Location: Lubbock, TX Posts: 1,671	Re: is this a true 4 bolt block? From the looks of it..looks like 4-bolt mains to me! Posted via Mobile Device __________________ 2006 GMC Sierra CCSB, 6.0 swap 2000 Chevy C3500 Crew Cab shortbed dually 1999 Chevy c2500 Crew Cab shortbed 1982 El Camino 350/350 1979 K5 2wd blazer bagged/bodied 1986 Monte Carlo SS 1991 Chevy CK SWB-67 clip and tailgate, bagged 350/700r4 1955 Chevy Bel Air 2014 Chevy Silverado ccsb

11-27-2010, 02:21 PM	#3
vtwinsport Registered User Join Date: Nov 2008 Location: edmonton, alberta Posts: 293	Re: is this a true 4 bolt block? I thought the end caps had to be 4 bolt as well? __________________ 76 Silverado, 2wd, long box, 350/th350, 3.42 posi, edelbrock performer 64cc heads, edelbrock 1405, 2101 intake, Hedman Headers, Comp Cam XE262 http://beerbreadbike.wordpress.com/

11-27-2010, 02:29 PM	#4
1BadSS NOT REALLY BANNED! Join Date: Jul 2004 Location: Shawnee, KS Posts: 1,072	Re: is this a true 4 bolt block? No __________________ 1987 Mustang Coupe - 2.7 Stroker, 78mm turbo, Stainless header, 3" Exh, FMIC, 160lb/hr Injectors, MS3, twin walbro 255's, 34psi. Eating V8's daily. 04 Pontiac GTO 04 Ford Mustang GT 68 C20 LWB stripper truck 73 K5 Cheyenne 76 C20 Sierra Crew SRW 88 K20 Suburban I'm not hammering on metal just to hammer, i'm creating a piece of art.

11-27-2010, 02:31 PM	#6
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,948	Re: is this a true 4 bolt block? theres no room for the extra bolts on the end caps.Definately a 4 bolt __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.

11-27-2010, 11:09 PM	#11
80SPORT Registered User Join Date: Mar 2008 Location: red deer alberta Posts: 777	Re: is this a true 4 bolt block? The big block motors with 4 bolt mains are 4 bolt on all caps.....this may be why the was some doubt about the small block 4 bolt units only using 2 bolts on the end caps...

11-29-2010, 02:15 AM	#13
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,948	Re: is this a true 4 bolt block? Most of the 2 bolt vs 4 bolt argument is just hype. I would bet a punch in the gut that nobody can show one example of a block that failed because of the block in a street engine. IM talking anything under 1.5hp per cubic inch. Im not talking about thrown together junk that was severely out of balance and broke a main cap but actual block failure. __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.

11-30-2010, 04:17 PM	#15
Captkaos www.73-87chevytrucks.com Join Date: Dec 1999 Location: Birmingham, AL Posts: 6,935	Re: is this a true 4 bolt block? Factory 4bolt mains are weaker than 2 bolt mains. We used to drag race a lot and I have broken more 4 bolts blocks than I care to mention. Ask any reputable race shop and they will tell you 2 bolts always hold up better, 4 bolts weaken the block webbing. If you want a strong block for the street a 2 bolt will do fine. If you have a 4 bolt use it. If you want ultimate strength get a 2 bolt block and have the mains machined for splayed caps. http://www.jegs.com/i/Eagle/356/C4102S/10002/-1 __________________ 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

11-30-2010, 06:40 PM	#17
silvereagle07 Registered User Join Date: Sep 2008 Location: Bailey, NC Posts: 2,462	Re: is this a true 4 bolt block? What's the casting number on the block? __________________ Jeramy '84 GMC project truck '85 Chevy 4X4 SOLD '07 Chevy Trailblazer SS 5th Annual SHPHC Car/Truck Show Pics http://67-72chevytrucks.com/vboard/s...d.php?t=543605 UPDATED PICS! CHECK 'EM OUT

12-01-2010, 08:45 AM	#18
BigBlocksRule Registered User Join Date: Jun 2008 Location: Lubbock, TX Posts: 2,047	Re: is this a true 4 bolt block? CaptKaos, how many 2-bolt blocks did you blow up drag racing? Chances are that you actually built a lot more 4-bolt blocks than 2. Just messin' with you The width of the cap where it mates to the block is the most critical area. A 2-bolt 400 is more like a big block with wide cap bases and registers, they'll take a lot more abuse because of this configuration. I do agree, though, a 2-bolt block converted splayed mains is the best we can do short of an aftermarket block. Second best is an early block with "2482" cast into the 4-bolt caps, they're nodular rather than grey iron, much stronger.

12-07-2010, 03:50 PM	#23
allengator Registered User Join Date: Dec 2010 Location: Burleson, Texas Posts: 596	Re: is this a true 4 bolt block? Add me to the "Nothing wrong with a 2 bolt" club... For a normally aspirated street engine, there are tons of other stuff to break first __________________ Allengator Outta the Blue (my band - available for hire in the DFW area!) 1980 Chevy SWB Pickup (build thread) 1951 Chevy Sedan Delivery 2004 Chevy Tahoe Z71 2011 Harley Davidson Street Glide 2018 Silverado Z71 Crew Cab

12-08-2010, 02:55 AM	#24
rayfinseats Registered User Join Date: Dec 2010 Location: sioux city, iowa Posts: 619	Re: is this a true 4 bolt block? Most of the 2 bolt vs 4 bolt argument is just hype. Agreed. Probably an 010 block.

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