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#1 |
Registered User
Join Date: Feb 2007
Location: Colorado Springs, Co
Posts: 1,939
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350 4 bolt
Someone told me all chevy 350s out of 72s came with 4 bolt, I disagreed, can anyone comfirm this block casting is 3970010 Thanks in advance
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#2 |
Registered User
Join Date: Apr 2007
Location: King City, Ontario, Canada
Posts: 974
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Re: 350 4 bolt
im not a information buff about stuff these trucks came with from the factory.
but i have herd that all trucks had "truck blocks" which were indeed 4 bolt mains. my 69 has a four bolt.
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- Jason If you can turn, Youre not going fast enough. Favorite caption: first car to 200 mph in the 1/4 mile, no parachute, drum brakes all the way around.. ..back when men were men. |
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#3 |
Burnouts are therapeutic
Join Date: Jun 2007
Location: lancaster, south carolina
Posts: 852
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Re: 350 4 bolt
I have two 350's with same casting number and I know for sure one is a 2 bolt main, but have not had pan off other one you can check numbers on nastyz28.com ,but you probaly need numbers off pad in front of pass. head .
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1969 CHEVELLE SS 1972 C10 ALMOST DAILY DRIVER 1968 C10 RUSTBUCKET (MISSION IMPOSSIBLE) 1972 PONTIAC LEMANS CONVERTIBLE (WIFE'S CAR) "My wife and I were happy for twenty years. Then we met." - Rodney Dangerfield "The difference between genius and stupidity is that genius has its limits." - Einstein |
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#4 |
Senior Member
Join Date: Jan 2003
Location: daytonabeach
Posts: 22,956
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Re: 350 4 bolt
thats a very common casting number i've seen more of them 2bolts than 4
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#5 |
Roadtrip!
![]() Join Date: Feb 2003
Location: Grand Rapids MN
Posts: 13,736
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Re: 350 4 bolt
Casting number is for a 350. Used for many years in low perf. to hi-perf. Could be had in 2 and 4 bolt mains...
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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 |
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#6 |
Chief Honcho In Charge
Join Date: Aug 2006
Location: Bentonville AR
Posts: 970
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Re: 350 4 bolt
2 bolts are good blocks. 4 bolt mains are used for high RPM or very high compression....not really needed but if you have 4 bolt does not hurt for daily driver apps.
Tim
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1992 1500 4x4 Shortbed 1984 Ford F250 Supercab Longbed 6.9L Diesel 1972 K10 Cheyenne Super Fleetside Short Bed - 350 - A/C 1971 VW SuperBeetle 1960 Wife 1984 Son 1986 Son 1989 Son Previous Trucks 1967 C10 SWB (1980-1981) 1971 C10 LWB (1998-2004) |
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#7 |
Registered User
Join Date: Mar 2006
Location: USA
Posts: 21,020
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Re: 350 4 bolt
Don't think so in the 10-30 series.What I've heard is that if they were from the C/40 and up series they were 4 bolt but I don't know...I've got a few 350 blocks around,one is a 4 bolt out of my old '69 Camaro I rolled over.If I really needed a 4 bolt I would make one out of a 2 bolt main block and go from there..
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#8 |
I am a Referee of life.
Join Date: Jun 2000
Location: Greensboro N.C.
Posts: 13,993
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Re: 350 4 bolt
From what research I have done;the casting # will not tell you whether it is 2 or 4 bolt main.Most performance engine builders prefer the 2 bolt main block even for very high performance because the webs are stronger and the aftermarket 4 bolt has splayed mains making them stronger and the webs remain stronger also.Also most agree that under 500 HP the 2 bolt is plenty strong.I have also been told the rods are weaker than the mains in a small block.
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The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil" |
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#9 |
Senior Member
Join Date: Mar 2004
Location: Nebraska
Posts: 583
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Re: 350 4 bolt
from the info i have found if your block has a 010 on the side by the motor mounts its is cast with thicker webs for the 4 bolt main.. making it stronger. now it is my understanding that if gm was short on 2 bolts it was not uncomon for them to drill out one of these as a 2 bolt.. it is still stronger than your average 2 bolt. if you put arp studs in a 2 bolt block it will be stro
nger than a 4 bolt... by the way the picture you see here of my engine is a 3970010 casting block. it has the 010 on the sides and in the back.. it was a 4 bolt. but my machinest made cast iron studs and threaded them into the outer bolt holes with lock tight. then milled off the tops. then it was machined for splayed caps.. Last edited by 57sailplane; 12-03-2007 at 07:00 PM. |
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#10 |
Special Order
![]() ![]() Join Date: Nov 2004
Location: Mt Airy, MD
Posts: 85,859
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Re: 350 4 bolt
A steel crank is more important that 2-bolt vs 4-bolt.4-bolt stabilize against deflection,but 2 extra holes weaken the casting.So a more rigid crank solves that w/o weaking the block.I`m not saying 4-bolt are weak.I still prefer them.Just saying the emphasis should be on the crank more than which block.A steel crank 4-bolt is the ultimate.
I always heard that truck 350s all had 4-bolts up through`75.A truck block is a hi-perf block.The difference between HD and HP comes from all the other moving parts.
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"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~ Last edited by special-K; 12-04-2007 at 11:30 AM. |
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#11 |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
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Re: 350 4 bolt
back to the original question, it is not uncommon at all to find a 4 bilt block in a 72 10 - 30 series truck.
It is also not uncommon to find a 10 20 high nickle block in a 72 10 - 30 truck too... which personally, I'd rather have the high nickle than the extra bolts. |
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#12 | |
Registered User
Join Date: Feb 2000
Location: Center City, MN, USA
Posts: 3,254
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Re: 350 4 bolt
Quote:
Accoring to my machine shop guy, who has been doing this long enough to have ordered heads for a 396 out of a catalog BEFORE they were ever sold to the public, for 99% of the people out there 2 or 4 bolts won't matter.
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'70 cab, '71 chassis, 383, TH350, NP205. '71 Malibu convertible '72 Malibu hard top Center City, MN |
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#13 | |
Senior Member
![]() Join Date: Dec 2006
Location: Studio City, Calif.
Posts: 2,873
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Re: 350 4 bolt
Quote:
But hey,when I'm pulling away with 10,000 lbs GVW flat out at 1500 RPM I'm thinking " Damn,good thing I got 4 bolt mains!"
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'69 GMC C2500 Custom Camper, 8 1/2' bed, New GM 350, NP 435 Close Ratio 4spd. Trans., 3.73 Dana-60 open.Camper and Trailer wiring, PS, PB, AC, tach , three gas tanks, stereo speakers, 2nd owner, Work-Truck supreme. Last edited by WorkinLonghorn; 12-04-2007 at 12:57 PM. |
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#14 |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
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Re: 350 4 bolt
when most ppl run a plow, they hold it at WOT in first, same thing when trying to drag junk through the mud or anything like that.
I do agree though, 99% of these build ups that are more for street than track don't need them. |
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#15 |
I am a Referee of life.
Join Date: Jun 2000
Location: Greensboro N.C.
Posts: 13,993
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Re: 350 4 bolt
So if you want the ultimate small block you need a 10 20 high nickle block with an 010 on the side and a steel crank.Then you have it machined for a splayed 4 bolt aftermarket main.Or you could just get an aftermarket block with all the above and probably save some money and even get a larger bore/stroke combo.Unless there's a class displacement requirement,or an originality issue building a 350 only makes sense if you already have good parts to build one.If you need a crank you can probably get a stroker for the same as a stock one,most other parts are the same,you can get better aftermarket for about the same money.
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The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil" |
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#16 |
I'm a poor spectator
Join Date: Aug 2006
Location: San Antonio, Tx
Posts: 2,287
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Re: 350 4 bolt
My k5's original block was a 4 bolt.
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#17 |
Senior Member
Join Date: Mar 2004
Location: Nebraska
Posts: 583
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Re: 350 4 bolt
the 4 bolt main cap is not installed to strengthen the block. the extra 2 bolts are there to keep your bearing alive. i agree that a forged crank is way better than cast but thats a totally differant story..
what happens and most people dont realize is that under drastic loads or high rpm major amounts of down force are applied to the mains via the piston and rod force down on the crank combined with the resistive force wich would be the load your are towing or you hit the trans brake at launch... the piston and rod want to push downward rotating the crank wile the restive load wants to stop crank rotation thus putting a major down force on the mains wether or not the crank is flexing is to no value to this problem and actually one that flexes will actually counteract the problem cause some of the downward force is taken up by flex.. what the 2 extra bolts are there for are not to keep the cap on but to keep it from squeezing togather.. you see the center of the cap is taking all the down force wich is also the weakest point of the cap. now just a slight flex of the cap downward in the middle is not a problem but if the cap flexes to much the sides of the cap will tend to squeeze inward toward the crank thus causing bearing failure. gm added the extra bolt to help the clamping force between the cap and the block to help eleviate this problem.. it can still slide but not nearly as easy.. that is also why the splayed cap is used because the outer bolt is put in at an angle thus making it near imposible for any cap flex and bearing failure. so you see for a steet engine being abused wile racing it or pulling the 4 bolt is a better deal.. keep in mind that i have read that an ARP studed 2 bolt is stronger than a stock 4 bolt and probably is cause you would get less flex from the stud and it has more clamping force than just 2 bolts. anyways i hope not to confusing... |
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#18 | |
Account Suspended
Join Date: Sep 2005
Location: Monroe, WA
Posts: 3,815
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Re: 350 4 bolt
Quote:
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IMHO the best buy is either a late-model roller block (one-piece seal) from your local junkyard or a new GMPP bare block (P/N 10066034) at around $700. The new factory block is a 4.00 finished bore with provision for a roller cam and a two-piece seal. You can drop a lot of money getting an old GEN I block up to spec. For folks that have never actually seen a high nickel, high tin block - this is what it looks like ![]() Last edited by Billla; 12-06-2007 at 11:12 PM. |
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