3970010 Block Q's - The 1947 - Present Chevrolet & GMC Truck Message Board Network

72MARIO · 12-20-2002, 11:48 PM

I have that block (actually my dads) and he wants to use for a 383 build up. When he took it apart it only had 2 Bolt mains . Just wondering if it can be changed to a 4 main without weeking the block? or will it be okay as just a 2 bolt block. Its going to be mainly built for towing, approx 400 hp 450 ft.lbs. torque.the Dart SR stock replacement Iron head.

crazy longhorn · 12-21-2002, 12:07 AM

You can upgrade to slayed aftermarket caps, but it gets a little pricey with caps & machine work. I would just install ARP main studs & run it.......my 383 is a 2 bolt block

bigjimzlll · 12-21-2002, 12:10 AM

yup...arp main studs(get the ones for a windage tray) and align hone...I would only use 4 bolt splayed caps with a forged crank with a blower or gobs of nitrous
Jim

72MARIO · 12-21-2002, 12:24 AM

what is a windage tray?>

bigjimzlll · 12-21-2002, 12:52 AM

its a tray that bolts to the main bolts that keeps oil off of the crank...can add 10 HP for around 20 bucks(actually dosent add, but saves the HP)

Longhorn Man · 12-21-2002, 12:58 AM

4 bolt mains are great if your gonna spin the snot out of your engine. If your making it a tow motor, then a 2 bol is fine. That engine will rarely see the high side of 3500 RPM.

Gene · 12-21-2002, 07:58 AM

I am guessing that the 3970010 came in both 2 bolt and 4 bolt mains because mine is a 4 bolt.

crazy longhorn · 12-21-2002, 08:35 AM

Yes, the 3970010 came both with 2 or 4 bolt caps. My 383 is built in a 2 bolt version.......gotta use those 10/20 blocks whenever you find them

robby · 12-21-2002, 08:48 PM

I had a 69 300 horse 350 with 186 small chamber big valve heads that was two bolt main in a chevelle I had when I was in the Marine Corps, everybody I beat never knew.

RACING29 · 12-21-2002, 09:46 PM

THats all you need(2 bolt main) unless your going over 600-700 horsepower. We have a 2 bolt block with good pistons and stock X rods with a cast crank and turn it 7200 rpm 30 laps ever weekend!

nu2-72 · 12-21-2002, 10:24 PM

What can anyone tell me about the 3970014 blocks ?

mikep · 12-21-2002, 10:44 PM

Chevrolet engineers and beancounters had absolutely no idea what they were doing when they specified 4 bolt mains and forged steel cranks in their higher load heavy duty engines. They did it just because they felt like spending more money on tooling, machining and extra parts. Car companies do that kind of thing because they like wasting money. It had nothing to do with increased bearing life . They used to love it when a customer would bring a seized engine in to be replaced. Gave the guys at the dealership something to do.

bigjimzlll · 12-22-2002, 12:29 AM

yea Mike..I know that was tongue and cheek, but sometimes you have to wonder what they were thinking with the 307 or torque swirl heads or the 2.8

mikep · 12-22-2002, 12:52 AM

Or that mini blazer in general. Especially the 5 speed manual trannies. Never have seen one last very long. Things pretty went to hell after "Boss" Ketterings departure.

I will have to differ with you on the 307. It did everything it was intended to do.

12-20-2002, 11:48 PM	#1
72MARIO Registered User Join Date: Nov 2000 Location: Huntsville Ontario Canada Posts: 4,051	3970010 Block Q's I have that block (actually my dads) and he wants to use for a 383 build up. When he took it apart it only had 2 Bolt mains . Just wondering if it can be changed to a 4 main without weeking the block? or will it be okay as just a 2 bolt block. Its going to be mainly built for towing, approx 400 hp 450 ft.lbs. torque.the Dart SR stock replacement Iron head. __________________ 1968 Suburban numbers matching all original truck now equipped with 6.0/4L80 on Accuair http://67-72chevytrucks.com/vboard/s...d.php?t=625017 1967 C/20 6.0/4L80 Roofing Truck 1990 V2500 Suburban "Plow Truck" 2005 TAHOE DD

12-21-2002, 12:07 AM	#2
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,402	You can upgrade to slayed aftermarket caps, but it gets a little pricey with caps & machine work. I would just install ARP main studs & run it.......my 383 is a 2 bolt block __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

12-21-2002, 12:10 AM	#3
bigjimzlll Senior Member Join Date: Dec 2001 Location: Redding,CA...USA Posts: 4,736	yup...arp main studs(get the ones for a windage tray) and align hone...I would only use 4 bolt splayed caps with a forged crank with a blower or gobs of nitrous Jim __________________ It's called "drag racing" if they called it "tic..tic..WHAM!..BANG! F*&K!!!", they'd have to keep the magazines under the counter with the other men's publications click the clicky to join the site.... http://67-72chevytrucks.com/vboard/payments.php 67 lwb..first hotrod in 25 years..540 best ET is 9.45 @ 141.44 Anderson,CA

12-21-2002, 12:24 AM	#4
72MARIO Registered User Join Date: Nov 2000 Location: Huntsville Ontario Canada Posts: 4,051	what is a windage tray?> __________________ 1968 Suburban numbers matching all original truck now equipped with 6.0/4L80 on Accuair http://67-72chevytrucks.com/vboard/s...d.php?t=625017 1967 C/20 6.0/4L80 Roofing Truck 1990 V2500 Suburban "Plow Truck" 2005 TAHOE DD

12-21-2002, 12:52 AM	#5
bigjimzlll Senior Member Join Date: Dec 2001 Location: Redding,CA...USA Posts: 4,736	its a tray that bolts to the main bolts that keeps oil off of the crank...can add 10 HP for around 20 bucks(actually dosent add, but saves the HP) Attached Images __________________ It's called "drag racing" if they called it "tic..tic..WHAM!..BANG! F&K!!!", they'd have to keep the magazines under the counter with the other men's publications click the clicky to join the site.... http://67-72chevytrucks.com/vboard/payments.php 67 lwb..first hotrod in 25 years..540 best ET is 9.45 @ 141.44 Anderson,CA Last edited by bigjimzlll; 12-21-2002 at 12:55 AM.*

12-21-2002, 12:58 AM	#6
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	4 bolt mains are great if your gonna spin the snot out of your engine. If your making it a tow motor, then a 2 bol is fine. That engine will rarely see the high side of 3500 RPM.

12-21-2002, 07:58 AM	#7
Gene Registered User Join Date: Aug 2002 Location: Muskogee, Oklahoma Posts: 2,914	I am guessing that the 3970010 came in both 2 bolt and 4 bolt mains because mine is a 4 bolt. __________________ 1971 SWB 4X4 Build BOARD MEMBER #5448 BOOMER SOONER!!!!

12-21-2002, 08:35 AM	#8
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,402	Yes, the 3970010 came both with 2 or 4 bolt caps. My 383 is built in a 2 bolt version.......gotta use those 10/20 blocks whenever you find them __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

12-21-2002, 08:48 PM	#9
robby Semper Fidelis Join Date: Dec 2001 Location: Cedar City, Utah Posts: 654	I had a 69 300 horse 350 with 186 small chamber big valve heads that was two bolt main in a chevelle I had when I was in the Marine Corps, everybody I beat never knew. __________________ 72 Chevy C 20 with 402 For sale 85 GMC K2500 83 Trans Am Cedar City, Utah (Missouri Native)

12-21-2002, 09:46 PM	#10
RACING29 Registered User Join Date: Jul 2002 Location: Tennessee, Morristown Posts: 355	THats all you need(2 bolt main) unless your going over 600-700 horsepower. We have a 2 bolt block with good pistons and stock X rods with a cast crank and turn it 7200 rpm 30 laps ever weekend! __________________ 1967 Chevy truck, R1 racing seats, 4 point racing harness, 4/6 drop, primered blue, soon to be shaved, 350- 060. over, flat top pistons, Eagle rods, Edelbrock Aluminum heads, 1.5 Scorpion roller rockers, Lunati 515" cam, mallory ignition, Holley 750 double pumper carb, Built 350 turbo trans, 2500-2800 boss hog stall, 20 gallon aluminum fuel cell!!!

12-21-2002, 10:24 PM	#11
nu2-72 Senior Member Join Date: Apr 2001 Location: Amazonia, Mo. USA Posts: 2,821	What can anyone tell me about the 3970014 blocks ? __________________ 72 3/4 4x4 350 4spd 72 3/4 4x4 350 auto 2004 Duramax Silverado 4x4 2006 Duramax Crew cab 4x4 2010 Harley Ultra Limited 2011 Harley Street Glide

12-21-2002, 10:44 PM	#12
mikep Used to have a truck Join Date: May 2002 Location: port orchard WA Posts: 1,552	Chevrolet engineers and beancounters had absolutely no idea what they were doing when they specified 4 bolt mains and forged steel cranks in their higher load heavy duty engines. They did it just because they felt like spending more money on tooling, machining and extra parts. Car companies do that kind of thing because they like wasting money. It had nothing to do with increased bearing life . They used to love it when a customer would bring a seized engine in to be replaced. Gave the guys at the dealership something to do. __________________ No truck :-(

12-22-2002, 12:29 AM	#13
bigjimzlll Senior Member Join Date: Dec 2001 Location: Redding,CA...USA Posts: 4,736	yea Mike..I know that was tongue and cheek, but sometimes you have to wonder what they were thinking with the 307 or torque swirl heads or the 2.8 __________________ It's called "drag racing" if they called it "tic..tic..WHAM!..BANG! F*&K!!!", they'd have to keep the magazines under the counter with the other men's publications click the clicky to join the site.... http://67-72chevytrucks.com/vboard/payments.php 67 lwb..first hotrod in 25 years..540 best ET is 9.45 @ 141.44 Anderson,CA

12-22-2002, 12:52 AM	#14
mikep Used to have a truck Join Date: May 2002 Location: port orchard WA Posts: 1,552	Or that mini blazer in general. Especially the 5 speed manual trannies. Never have seen one last very long. Things pretty went to hell after "Boss" Ketterings departure. I will have to differ with you on the 307. It did everything it was intended to do. __________________ No truck :-(



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