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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Bitzer! on March 07, 2008, 07:34:25 am

Title: 2 or 4
Post by: Bitzer! 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
Title: Re: 2 or 4
Post by: HAULIN IT 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     
Title: Re: 2 or 4
Post by: Bitzer! 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
Title: Re: 2 or 4
Post by: JJSZABO on March 07, 2008, 08:43:46 am
Bitzer - what is fuel costs "across the pond" ?
Title: Re: 2 or 4
Post by: Captkaos 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.
Title: Re: 2 or 4
Post by: Bitzer! on March 07, 2008, 09:20:10 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!
Title: Re: 2 or 4
Post by: Captkaos 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.

Title: Re: 2 or 4
Post by: VileZambonie 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.
Title: Re: 2 or 4
Post by: 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.
Title: Re: 2 or 4
Post by: red4wd 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.  
Title: Re: 2 or 4
Post by: HAULIN IT 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
Title: Re: 2 or 4
Post by: Bitzer! 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
Title: Re: 2 or 4
Post by: JJSZABO on March 07, 2008, 11:09:32 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
Title: Re: 2 or 4
Post by: Bitzer! 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?
Title: Re: 2 or 4
Post by: Captkaos 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?
Title: Re: 2 or 4
Post by: choptop on March 07, 2008, 08:38:41 pm

[/quote]

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 ;)

I  just paid $3.09 for gas and saw $3.93 deisel here in West Texas...Trade ya    I have a buddy running over 600 hp with nitrous on a 2 bolt with the splayed caps. He had a 4 bolt but is shelled out at the track with a little less power
Title: Re: 2 or 4
Post by: Bitzer! on March 08, 2008, 04:37:09 am

Is this for the crewcab?

yup its for the crew-cab = where do I look for numbers! :)

 Restoration a little slow due to work, weather and space. I'm so envious of you guys over there with huge double garages etc. I have 3foot at the front and 2foot either side to work in!

I  just paid $3.09 for gas and saw $3.93 deisel here in West Texas...Trade ya - You sure? thats a litre not a gallon :o
Title: Re: 2 or 4
Post by: choptop on March 08, 2008, 08:06:57 am
I see the error of my ways.....I was thinking gallons not liters.  My wallet aches just thinking about it.
Title: Re: 2 or 4
Post by: Bitzer! on March 08, 2008, 03:25:13 pm
If it is a Quadrajet it will have numbers stamped on it.
If it is a Quad, you should be fine swapping it.

had a quick look earlier- under the edlebrock air filter I have..........a holley!
Title: Re: 2 or 4
Post by: Captkaos on March 08, 2008, 09:32:48 pm
Still will have numbers stamped on it, generally on the body.
Title: Re: 2 or 4
Post by: Bitzer! on March 11, 2008, 05:29:57 pm
Okay guys - had a nose but cant see any numbers    :(   or maybe I'm looking in the wrong place!  HELP
Title: Re: 2 or 4
Post by: Captkaos on March 11, 2008, 05:34:23 pm
Look on the side of the carb behind the bowls.
Title: Re: 2 or 4
Post by: Bitzer! on March 11, 2008, 05:37:19 pm
could you give me an idea of what the numbers should look like or just a part number?

cheers for mega quick reply!
Title: Re: 2 or 4
Post by: Captkaos on March 11, 2008, 06:00:03 pm
It will be about 8 numbers long.  It might be on the choke horn also.
Title: Re: 2 or 4
Post by: Bitzer! on March 11, 2008, 06:04:39 pm
Thanks Capt, I'll look tomorrow as its now 11pm here!
Title: Re: 2 or 4
Post by: red4wd on March 11, 2008, 06:06:24 pm
It should look something like this...

(http://arhunter.net/ads/3310.jpg)
Title: Re: 2 or 4
Post by: Bitzer! on March 11, 2008, 06:08:24 pm
Diamond Red  ;)  cheers
Title: Re: 2 or 4
Post by: Bitzer! on March 13, 2008, 05:07:22 pm
okay guys- question time! the numbers off the carb =  3310-6      D120  can you identify what Holley it is?

And the next question. I assume this is something to do with cruise control? Can I isolate it and put the speedo cable into the back of the speedo? Or is it needed!!

Title: Re: 2 or 4
Post by: Bitzer! on March 13, 2008, 05:10:17 pm
oooops it has a serial number of = 315728

cheers
Title: Re: 2 or 4
Post by: red4wd on March 13, 2008, 05:47:38 pm
Bitzer...that is a 750 cfm carb with vaccum secondaries.
Title: Re: 2 or 4
Post by: Bitzer! on March 13, 2008, 05:58:54 pm
I guess thats a pretty big bucket then!! Any guesses at the picture?     ;)
Title: Re: 2 or 4
Post by: Bitzer! on March 14, 2008, 09:27:14 am
Please dont let me down guys! If its the cruise control (thats obsolete) can I remove the cable and stick it straight into the back of the clock?

 :)

cheers
Title: Re: 2 or 4
Post by: Captkaos on March 14, 2008, 09:53:21 am
It is the Cruise control.  I don't think the cable will be long enough to reach, but if you can get a single cable for a truck without cruise you can remove it.
BTW, those cruise setup are junk in my opinion.
Title: Re: 2 or 4
Post by: Bitzer! on March 14, 2008, 11:29:59 am
Cheers  Kaptkaos   :)  It doesn't work anyway and I'd rather remove it and have it gone!

I'm sure I can order a cable somewhere   :D

As always, many thanks for the help

Bitzer