urban legend , truth or trash ????? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

*wolfthing2000* · 02-14-2005, 01:13 PM

The legend is: all 350 truck engines were 4-bolt mains. Is this so???

skokie · 02-14-2005, 01:15 PM

I have seen both but by all means I am not a expert.

extd56 · 02-14-2005, 01:18 PM

I would say NO. I have seen a lot of truck motors that were 2 bolt, nothing wrong with a 2 bolt.

MrShelley · 02-14-2005, 01:24 PM

I say no as well. I had a 350 2-bolt in my truck back in the day.

Peregrine · 02-14-2005, 01:29 PM

If they were all 4 bolts, engine builders/sellers wouldn't brag about motors being 4 bolts.

Gene · 02-14-2005, 02:37 PM

Definitely NO. Not all 350's are 4 bolt mains. Take a 3970010 for instance, it could be a 2 or 4 bolt main.

cdowns · 02-14-2005, 02:38 PM

4bolts are overrated

krue · 02-14-2005, 03:05 PM

Better to have and not need, than to need and not have.

stepside454 · 02-14-2005, 03:31 PM

Id sell the 4 bolt for some useful cash to somebody who thinks 4 bolts are better & than use 2 bolt...ive done it before, & will do it again

67chevemall · 02-14-2005, 03:36 PM

I have a 4 bolt 4 sale!

GreyHoundSteve · 02-14-2005, 03:36 PM

My truck 350 is a 2 bolt.

arkracing · 02-14-2005, 03:40 PM

not true.

plenty of trucks had 2-bolt motors....even 3/4 and 1 tons...although those are the truck you would most likely find a 4-bolt in.

2-bolts are good to 500hp anyway (just use MainStuds/quality fasteners)...and if you build a motor that pushing that you should be running a new GMPP block or Dart or something and has provisions for a roller cam

shortymac83 · 02-14-2005, 04:16 PM

Quote:

Originally Posted by arkracing

not true.

plenty of trucks had 2-bolt motors....even 3/4 and 1 tons...although those are the truck you would most likely find a 4-bolt in.

2-bolts are good to 500hp anyway (just use MainStuds/quality fasteners)...and if you build a motor that pushing that you should be running a new GMPP block or Dart or something and has provisions for a roller cam

an off topic question, do they make main girdles for chevy motors? I ask because I see them availible from everyone for olds motors, but not for chevies...I'd assume that since you can pretty much fall over a 4 bolt main block, that it's not necessary?

*wolfthing2000* · 02-15-2005, 01:11 PM

Very interesting!! So a Myth it is seems!! I was also told they used only 4-bolts in the bigger station wagons and Suburbans.
Dave

arkracing · 02-15-2005, 04:47 PM

lots of "theories" on what they put them in and identify them by....i don't think anyone reall knows...maybe not even GM.

they were more popular in heavy trucks, burbs, big station wagons - but not all of them had 4-bolts, and i'm pretty sure alot of the performace years - camaro's etc had some 4-bolts.

as far as the main girdles - i've seen them before but don't know who makes them - you would have to be pushing some serious hp/tq numbers to need one. - most guys just go with a dart/world block if they need that much beef..and you can get them with billet steel splayed main caps

boraxman · 02-15-2005, 04:51 PM

I had a 4 bolt 350 in a(original) 69 Camaro SS I once owned.

6869704X4 · 02-15-2005, 05:12 PM

I heard that all truck V8s were 4 bolt. We know thats not true.
I have two 69 300horse 350s(one is the original motor in my 69 Camaro SS) both are Tonawanda engines, one is a 4 bolt, one is a 2. I'm guessing supply and demand determined if a vechicle got 4 or 2 bolts.

junkyardjohn · 02-15-2005, 05:35 PM

I'VE BUILT MORE THAN A FEW ENGINES, & MAYBE A 4 BOLT MAIN IS OVERKILL BUT I WOULDN'T CONSIDER BUILDING A TWO BOLT WHEN 4 BOLT BLOCKS ARE SO PLENTIFUL. THEY ARE THE SAME COST FOR THE BLOCK & THE SAME TO REBUILD SO WHY NOT?? . ANYBODY GOT A THEORY ON WHY 2 BOLT BLOCKS ARE SO MUCH STRONGER & BETTER THAN 4 BOLT BLOCKS.??

(QUOTE) most guys just go with a dart/world block if they need that much beef..and you can get them with billet steel splayed main caps (QUOTE)

EXCEPT THE COST OF THEM MAKES IT IMPOSSIBLE FOR ME. FOR THE COST OF A DART BLOCK WITH SPLAYED CAPS, I CAN BUILD A COMPLETE 4 BOLT 350 FROM CARB TO PAN.

JOHN

stepside454 · 02-15-2005, 05:41 PM

as far as same cost, I geuss that depends. here I can get 2 bolt 350s for little or nothin...but guys are gettin 250.00+ for 4 bolt bare blocks...so depending on what its usage was, Id rather spend the 250.00 elsewhere. Ive never busted a 2 bolt in all my years, however ,I do believe 4 bolts are crucial in heavy towing applications

junkyardjohn · 02-15-2005, 06:11 PM

OUT HERE IN NV. YOU CAN GET A BARE 350 BLOCK FOR $50 -$75 AT MOST ANY JUNKYARD , & IT DOESN'T MATTER IF IT'S A 2 OR 4 BOLT BLOCK. FOR $250 + YOU CAN GET A COMPLETE RUNNING ENGINE.

JOHN

**too much stuff** · 02-15-2005, 06:40 PM

I asked a buddy about this who owns a machine shop and has built many 350s from stock to built. His opinion is a 4 bolt block is good for hi horse/ torque applications. He also said about 9 out of 10 stock 4 bolts will have at least one main bolt that is not even close to torque specs. (usually 2 will be loose).
And to answer the main question, trucks came with 2 or 4 bolt mains.

SLS · 02-16-2005, 03:52 AM

I've got a #010 350 that came from Tonawanda.....

....and I've been waiting to pull the pan this spring to see if it's a 2-bolt or a 4-bolt.

*wolfthing2000* · 02-24-2005, 12:12 PM

It gets better!!! I pulled the engine ( owner said it was original and tag on truck has an option listed for the 350 c.i.) I started checking numbers for 2 or 4 bolt and the block numbers say 400 c.i. and the head has 350 numbers!!!!
Still need to pull apart to find out for sure.

68C15 · 02-24-2005, 12:31 PM

wolfthing, thats the only true way to know.
there is nothing wrong with a 2 bolt. around here they are using them in street stocks for the dirt circle. some guys are even running upwards of 600 HP on them.
truth be told the main caps is not the weak point. all the extra bolts do is HELP keep the main bearing journal round under SEVERE low RPM torque load or idiot drivers side stepping the clutch.

Doug76 · 02-24-2005, 07:30 PM

Its always been a debate and always will be..Does anyone personally know anyone who has had a problem with strength after building a 2 bolt motor?

02-14-2005, 01:13 PM	#1
wolfthing2000 Account Suspended Join Date: Oct 2004 Posts: 1,276	urban legend , truth or trash ????? The legend is: all 350 truck engines were 4-bolt mains. Is this so???

02-14-2005, 01:15 PM	#2
skokie Registered User Join Date: Oct 2003 Location: San Jose Ca. Posts: 3,300	I have seen both but by all means I am not a expert. __________________ RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234

02-14-2005, 01:24 PM	#4
MrShelley Too Many Clubs Club Join Date: Jul 2003 Location: Kilgore, Texas Posts: 443	I say no as well. I had a 350 2-bolt in my truck back in the day. __________________ How I installed my air bags...

02-14-2005, 01:29 PM	#5
Peregrine Registered User Join Date: Sep 2004 Location: Louisville, Ky Posts: 329	If they were all 4 bolts, engine builders/sellers wouldn't brag about motors being 4 bolts. __________________ Brian 72 C10 longbed 350/th400 Let the world change you and you will change the world.

02-14-2005, 02:37 PM	#6
Gene Registered User Join Date: Aug 2002 Location: Muskogee, Oklahoma Posts: 2,914	Definitely NO. Not all 350's are 4 bolt mains. Take a 3970010 for instance, it could be a 2 or 4 bolt main. __________________ 1971 SWB 4X4 Build BOARD MEMBER #5448 BOOMER SOONER!!!!

02-14-2005, 01:18 PM	#3
extd56 Senior Member Join Date: Nov 2004 Location: Vacaville, CA Posts: 2,272	I would say NO. I have seen a lot of truck motors that were 2 bolt, nothing wrong with a 2 bolt.

02-14-2005, 02:38 PM	#7
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	4bolts are overrated __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

02-14-2005, 03:05 PM	#8
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,450	Better to have and not need, than to need and not have. __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

02-14-2005, 03:31 PM	#9
stepside454 Registered User Join Date: Nov 2003 Location: st. louis area Posts: 1,551	Id sell the 4 bolt for some useful cash to somebody who thinks 4 bolts are better & than use 2 bolt...ive done it before, & will do it again __________________ 75 GMC C-15 short/step factory 454, lowered

02-14-2005, 03:36 PM	#10
67chevemall Registered User Join Date: Apr 2003 Location: NB Posts: 3,367	I have a 4 bolt 4 sale! __________________ 1968 Chevy C10 307 3ott fleetside 1967 Chevy C/10 V8, 3spd, fleetside lwb.Sold 1967 Chev C/10 step, 383, M21. SOLD

02-14-2005, 03:36 PM	#11
GreyHoundSteve Registered User Join Date: Oct 2004 Location: DFW TX Posts: 769	My truck 350 is a 2 bolt.

02-14-2005, 03:40 PM	#12
arkracing Weekend Warrior Join Date: Oct 2004 Location: CT Posts: 1,787	not true. plenty of trucks had 2-bolt motors....even 3/4 and 1 tons...although those are the truck you would most likely find a 4-bolt in. 2-bolts are good to 500hp anyway (just use MainStuds/quality fasteners)...and if you build a motor that pushing that you should be running a new GMPP block or Dart or something and has provisions for a roller cam __________________ -'07 GMC Sierra K2500HD -'66 C10 Suburban -'68/'71 K20 Service Bed Project -'69 Chevy C30 Mason Dump -'33Ford P/U 396ChevyPowered

02-15-2005, 01:11 PM	#14
wolfthing2000 Account Suspended Join Date: Oct 2004 Posts: 1,276	Very interesting!! So a Myth it is seems!! I was also told they used only 4-bolts in the bigger station wagons and Suburbans. Dave

02-15-2005, 04:47 PM	#15
arkracing Weekend Warrior Join Date: Oct 2004 Location: CT Posts: 1,787	lots of "theories" on what they put them in and identify them by....i don't think anyone reall knows...maybe not even GM. they were more popular in heavy trucks, burbs, big station wagons - but not all of them had 4-bolts, and i'm pretty sure alot of the performace years - camaro's etc had some 4-bolts. as far as the main girdles - i've seen them before but don't know who makes them - you would have to be pushing some serious hp/tq numbers to need one. - most guys just go with a dart/world block if they need that much beef..and you can get them with billet steel splayed main caps __________________ -'07 GMC Sierra K2500HD -'66 C10 Suburban -'68/'71 K20 Service Bed Project -'69 Chevy C30 Mason Dump -'33Ford P/U 396ChevyPowered

02-15-2005, 04:51 PM	#16
boraxman Keepin an eye out Join Date: Feb 2003 Location: So.Cal Posts: 3,921	I had a 4 bolt 350 in a(original) 69 Camaro SS I once owned. __________________ 1970 Chevy C10 SWB 5.3 1996 Toyota Tacoma SR5 4x4 2007 Vespa GTS 250 Scooter ZIP 91351



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02-15-2005, 05:12 PM	#17
6869704X4 Registered User Join Date: Jul 2002 Location: SE NM Posts: 769	I heard that all truck V8s were 4 bolt. We know thats not true. I have two 69 300horse 350s(one is the original motor in my 69 Camaro SS) both are Tonawanda engines, one is a 4 bolt, one is a 2. I'm guessing supply and demand determined if a vechicle got 4 or 2 bolts. __________________ The more I learn about women, the more I love my truck.

02-15-2005, 05:35 PM	#18
junkyardjohn Registered User Join Date: Aug 2001 Location: SOMERSET KY. Posts: 6,427	I'VE BUILT MORE THAN A FEW ENGINES, & MAYBE A 4 BOLT MAIN IS OVERKILL BUT I WOULDN'T CONSIDER BUILDING A TWO BOLT WHEN 4 BOLT BLOCKS ARE SO PLENTIFUL. THEY ARE THE SAME COST FOR THE BLOCK & THE SAME TO REBUILD SO WHY NOT?? . ANYBODY GOT A THEORY ON WHY 2 BOLT BLOCKS ARE SO MUCH STRONGER & BETTER THAN 4 BOLT BLOCKS.?? (QUOTE) most guys just go with a dart/world block if they need that much beef..and you can get them with billet steel splayed main caps (QUOTE) EXCEPT THE COST OF THEM MAKES IT IMPOSSIBLE FOR ME. FOR THE COST OF A DART BLOCK WITH SPLAYED CAPS, I CAN BUILD A COMPLETE 4 BOLT 350 FROM CARB TO PAN. JOHN __________________ junkyardjohn 69 1 TON TOW TRUCK // 84 4WD CUCV BLAZER// 85 1 TON 4WD STAKE TRUCK// 86 M1031 5/4 TON 4WD CUCV// ALOT OF OLD TRUCKS FOR ONE OLD MAN TO DRIVE. THERES ROOM FOR ALL OF GODS CREATURES RIGHT NEXT TO MY MASHED POTATOES// LIFE MEMBER OF P.E.T.A (PEOPLE EATING TASTY ANIMALS) DON'T RENT U-HAUL ALWAYS TELL THE TRUTH IT WILL AMAZE PART OF THE PEOPLE & ASTONISH THE REST

02-15-2005, 05:41 PM	#19
stepside454 Registered User Join Date: Nov 2003 Location: st. louis area Posts: 1,551	as far as same cost, I geuss that depends. here I can get 2 bolt 350s for little or nothin...but guys are gettin 250.00+ for 4 bolt bare blocks...so depending on what its usage was, Id rather spend the 250.00 elsewhere. Ive never busted a 2 bolt in all my years, however ,I do believe 4 bolts are crucial in heavy towing applications __________________ 75 GMC C-15 short/step factory 454, lowered

02-15-2005, 06:11 PM	#20
junkyardjohn Registered User Join Date: Aug 2001 Location: SOMERSET KY. Posts: 6,427	OUT HERE IN NV. YOU CAN GET A BARE 350 BLOCK FOR $50 -$75 AT MOST ANY JUNKYARD , & IT DOESN'T MATTER IF IT'S A 2 OR 4 BOLT BLOCK. FOR $250 + YOU CAN GET A COMPLETE RUNNING ENGINE. JOHN __________________ junkyardjohn 69 1 TON TOW TRUCK // 84 4WD CUCV BLAZER// 85 1 TON 4WD STAKE TRUCK// 86 M1031 5/4 TON 4WD CUCV// ALOT OF OLD TRUCKS FOR ONE OLD MAN TO DRIVE. THERES ROOM FOR ALL OF GODS CREATURES RIGHT NEXT TO MY MASHED POTATOES// LIFE MEMBER OF P.E.T.A (PEOPLE EATING TASTY ANIMALS) DON'T RENT U-HAUL ALWAYS TELL THE TRUTH IT WILL AMAZE PART OF THE PEOPLE & ASTONISH THE REST

02-15-2005, 06:40 PM	#21
too much stuff Roadtrip! Join Date: Feb 2003 Location: Grand Rapids MN Posts: 13,704	I asked a buddy about this who owns a machine shop and has built many 350s from stock to built. His opinion is a 4 bolt block is good for hi horse/ torque applications. He also said about 9 out of 10 stock 4 bolts will have at least one main bolt that is not even close to torque specs. (usually 2 will be loose). And to answer the main question, trucks came with 2 or 4 bolt mains. __________________ 67 gmc custom lwb dakota truck. Sold...And bought back 69 swb 4x4 project (in progress) 70 c-10 lwb texas truck 70 4x4/BB/bkts/posi/tach(retired) 70 swb (wifes) 70 jimmy camper 71 K-5 factory 2wd 71 cheyenne 4x4/tach/posi/ plow rig 71 Cheyenne20 BB, buckets, tach, tilt, 4 speed 72 jimmy CST wyoming rig 72 jimmy Colorado rig 72 lifted texas 4x4 3/4 ton burb 65 fury conv. 383/auto 65 chrysler 300 "L" 413 auto

02-16-2005, 03:52 AM	#22
SLS Finish the'71..or bust! Join Date: Jun 2003 Location: Nashville, TN. Posts: 441	I've got a #010 350 that came from Tonawanda..... ....and I've been waiting to pull the pan this spring to see if it's a 2-bolt or a 4-bolt.

02-24-2005, 12:12 PM	#23
wolfthing2000 Account Suspended Join Date: Oct 2004 Posts: 1,276	It gets better!!! I pulled the engine ( owner said it was original and tag on truck has an option listed for the 350 c.i.) I started checking numbers for 2 or 4 bolt and the block numbers say 400 c.i. and the head has 350 numbers!!!! Still need to pull apart to find out for sure.

02-24-2005, 12:31 PM	#24
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	wolfthing, thats the only true way to know. there is nothing wrong with a 2 bolt. around here they are using them in street stocks for the dirt circle. some guys are even running upwards of 600 HP on them. truth be told the main caps is not the weak point. all the extra bolts do is HELP keep the main bearing journal round under SEVERE low RPM torque load or idiot drivers side stepping the clutch. __________________ Man rule #77...if you own a 67 stepside with a caddy 472 you will never be in danger of loosing you man card

02-24-2005, 07:30 PM	#25
Doug76 This S&*! Is expensive! Join Date: Feb 2005 Location: Mechanicsville,Va Posts: 57	Its always been a debate and always will be..Does anyone personally know anyone who has had a problem with strength after building a 2 bolt motor?

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