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Author Topic: 2 or 4  (Read 12282 times)

Offline Bitzer!

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2 or 4
« on: March 07, 2008, 07:34:25 am »
Guys- how can you differentiate between the 2 / 4 bolt main? Are there any obvious tell tale signs without taking the sump off?

I found a number GM3970010 at the back of the block but it seems to be a "general" number not specific to one engine and wondered where I should look for more numbers without ripping it apart.

andy ideas?

cheers

Bitzer
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1979 GMC CrewCab  C20 1t
454 750 Holley,TH350, 14bolt diff fully floating
Why aren't there 8 days in a week!
A K5 rolling shell *new addition*

Offline HAULIN IT

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Re: 2 or 4
« Reply #1 on: March 07, 2008, 08:21:24 am »
The Ol' 010, If I had the money I/friends spent when we were young on 2 bolts that were supposed to be 4 bolts. The older books (published about 1980) had that as all 4 bolt mains, they were way off. Some with that number did (I do have a couple) but many were not. I guess it depends on the cost, how important it is to you & how easy it is to pull the pan as to what you do. If the price is right, I would take it anyway, you never know what you may need someday. Good Luck & we'll hope you got a 4 bolt, Lorne     
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Offline Bitzer!

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Re: 2 or 4
« Reply #2 on: March 07, 2008, 08:37:51 am »
Unfortunately its sat on the deck and I have no means of lifting it  :-\ and we all know they're not the lightest! It was donated to me by my nice Bro but all he can tell me it came from a Blazer and assume its a 350. Rattly when it came out and needs re-building.

my dilema is I have a 454 (rattly!) in situ and running in the truck. I don't know if this is a 2/4 either! The idea is to "build" the 4bolt (if either is) but was hoping for an easy way to tell!

cheers

Bitzer
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1979 GMC CrewCab  C20 1t
454 750 Holley,TH350, 14bolt diff fully floating
Why aren't there 8 days in a week!
A K5 rolling shell *new addition*

Offline JJSZABO

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Re: 2 or 4
« Reply #3 on: March 07, 2008, 08:43:46 am »
Bitzer - what is fuel costs "across the pond" ?
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Jeff

86 Chevy C-10
350, TH400
Ex father and son project (son lost interest)

Son regained interest when truck was almost completed

Offline Captkaos

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Re: 2 or 4
« Reply #4 on: March 07, 2008, 09:02:48 am »
No way without pulling the pan off, but there is nothing wrong with a 2 bolt block especially for street use.  If you are concerned, just have it machined for splayed caps and it will be stronger than a 4 bolt.  Unless you are building a drag motor, 2bolts are up to the task.
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Offline Bitzer!

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Re: 2 or 4
« Reply #5 on: March 07, 2008, 09:20:10 am »
Quote from: JJSZABO on March 07, 2008, 08:43:46 am
Bitzer - what is fuel costs "across the pond" ?

totally outrageous m8! a litre petrol is £1.12 so I guess thats about $2.30

I'm just very thankful I have a diesel car for everyday use that gets about 55mpg ;)

As for the donkey (engine!) i'd prefer to build the 4 if it was "sat there". Not heard of splayed caps so can't comment lol.  Up to 2months ago the idea was full works with blower and semi-strip use. Now the plans have changed due to little feet arriving in August  ;D so down-scaling a little!
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1979 GMC CrewCab  C20 1t
454 750 Holley,TH350, 14bolt diff fully floating
Why aren't there 8 days in a week!
A K5 rolling shell *new addition*

Offline Captkaos

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Re: 2 or 4
« Reply #6 on: March 07, 2008, 10:01:04 am »
This is a splayed cap setup.  http://store.summitracing.com/partdetail.asp?part=ESP%2DC4102S&autoview=sku

Sweet, congrats on the new addition.

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Offline VileZambonie

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Re: 2 or 4
« Reply #7 on: March 07, 2008, 10:11:09 am »
After the last broken 4 bolt I pulled apart I can honestly say I've never seen a 2 bolt fail like that. I have plenty of faith in 2 bolt blocks and if I was going to go nuts with it would splay new caps like Chris said.
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Offline Captkaos

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Re: 2 or 4
« Reply #8 on: March 07, 2008, 10:16:01 am »
It is my personal experience that 4 bolts are WEAKER (yeah, I said it :D ) than 2 bolt mains, and you can safely get 500hp out of a stock 2bolt.  Now if you are beating it on the track, splay the mains.
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Offline red4wd

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Re: 2 or 4
« Reply #9 on: March 07, 2008, 10:17:19 am »
I know my buddy that builds 421's and 434's with stock blocks would rather start with a two bolt block and the splayed cap set.  
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Offline HAULIN IT

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Re: 2 or 4
« Reply #10 on: March 07, 2008, 10:20:58 am »
I do agree with you guys & Red is exactly right. With the 400's, if the 4 bolt isn't cracked when you get it checked, it will most likely be shortly after you start using it hard. Lorne
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Offline Bitzer!

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Re: 2 or 4
« Reply #11 on: March 07, 2008, 10:27:19 am »
Much appreciated guys  :) Its difficult to get hands on opinions "over here" where they're not biased to selling you loads.  Looks like I'll build the 350 as parts over here are easier / cheaper to get hold of and "cap" it if only a 2bolt. I reckon with $2000-00 it should make the right noises but maybe not as quick as I'd hoped.

One thing for sure, my "new" likkle person will be safer in the truck than the rubbish European cars we have  ;D
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1979 GMC CrewCab  C20 1t
454 750 Holley,TH350, 14bolt diff fully floating
Why aren't there 8 days in a week!
A K5 rolling shell *new addition*

Offline JJSZABO

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Re: 2 or 4
« Reply #12 on: March 07, 2008, 11:09:32 am »
Quote from: Captkaos on March 07, 2008, 10:16:01 am
It is my personal experience that 4 bolts are WEAKER (yeah, I said it :D ) than 2 bolt mains, and you can safely get 500hp out of a stock 2bolt.  Now if you are beating it on the track, splay the mains.

WOW - now that's a statement.  You are making me LOVE my 2 bolt!!! ;D
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Jeff

86 Chevy C-10
350, TH400
Ex father and son project (son lost interest)

Son regained interest when truck was almost completed

Offline Bitzer!

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Re: 2 or 4
« Reply #13 on: March 07, 2008, 04:13:25 pm »
another quick one! Do carbs have any easy identification marks? Maybe I take the big bucket off the 454 and stick it on the 350? any forseable issues?
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1979 GMC CrewCab  C20 1t
454 750 Holley,TH350, 14bolt diff fully floating
Why aren't there 8 days in a week!
A K5 rolling shell *new addition*

Offline Captkaos

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Re: 2 or 4
« Reply #14 on: March 07, 2008, 07:24:34 pm »
If it is a Quadrajet it will have numbers stamped on it.
If it is a Quad, you should be fine swapping it.

Is this for the crewcab?
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