Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

?4 Bolt Main?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Kajun_K5, Sep 7, 2001.

  1. Kajun_K5

    Kajun_K5 Registered Member

    Joined:
    Jul 9, 2001
    Posts:
    48
    Likes Received:
    0
    Location:
    Lafayette, Louisiana
  2. Zepplin

    Zepplin 1/2 ton status

    Joined:
    Aug 29, 2000
    Posts:
    920
    Likes Received:
    0
    Location:
    Bay City, MI 48706
    If you can get one easily go for it. If not, a 2 bolt will hold up fine if you use studs instead of the bolts. A stud kit will double the strength compared to stock main bolts.

    I guess if you are drag racing you may want a 4 bolt but, for a motor in a Blazer replacing the bolts with studs will be more than sufficient. I have studs in the 2 bolt 496 block I have.

    74 Blazer
    Zepplin
    Check out my Blazer <a target="_blank" href=http://community.webshots.com/user/zepplin1976>http://community.webshots.com/user/zepplin1976</a>
     
  3. Mreetz

    Mreetz 1/2 ton status

    Joined:
    Jun 26, 2001
    Posts:
    1,282
    Likes Received:
    0
    Location:
    Subs of Denver, Colorado
    DITTO, get the 4 bolt if its available. 2 bolt is fine with the studs.

    1984 K-5
    4" lift
    35x12.5 MTs
    buildin a 400 for it, any info greatly appreciated
     
  4. 4 bolt mains are for extreme duty/ race engines. You are going to be hard pressed to give your engine enough use/ abuse to warrent the cost. If you are going to drive at HIGH RPMS (5500+), then consider it, if not, replace the main bolts with studs and be done with it.

    God has a hard on for Marines, because we keep Heaven chock full of fresh souls!
     
  5. Mr.Chevy4x4

    Mr.Chevy4x4 1/2 ton status

    Joined:
    Jun 16, 2000
    Posts:
    1,932
    Likes Received:
    0
    Location:
    Sims, NC
    I have seen a test where a 2 bolt main 350 with a b&amp;m supercharger made over 550 horsepower with the stock main bolts and made 26 dyno pulls to 5500 RPM with no failure. A 2 bolt block will handle what ever you throw at it as far as making it a truck motor. Actually the stock shouldered bolts prevent "cap walk" better than studs do.

    '85 K5 : Run it til it breaks, then fix it and go again!
     
  6. wayne

    wayne 3/4 ton status

    Joined:
    Feb 1, 2001
    Posts:
    6,178
    Likes Received:
    0
    Location:
    Carlisle, Pa
    IMHO no. The 4 bolt block is prown to stress cracks on the outer main bolts. I have run many 2 bolt main blocks with the factory bolts without any problems. If you want more strength you can use studs or you can have a 2 bolt block drilled and tapped for Milodon angled side bolt's which is much stronger then a stock 4 bolt.

    See <a target="_blank" href=http://coloradok5.com/gallery/Waynes-Toy>Project Mighty Mouse</a> here.
    <font color=blue>Wayne<font color=blue>
    <font color=blue>Happy Trails<font color=blue>
     
  7. Neil

    Neil 1/2 ton status

    Joined:
    Jun 10, 2001
    Posts:
    275
    Likes Received:
    0
    Location:
    Dothan,Alabama
    I have done drag racing and been around Chevy small blocks for 10 years and never seen a motor fail thru the mains anyways. 2 bolts are fine. If you insist on a 4 bolt, I have one here that is a 1970 350 standard bore if you want to come get it. block and main caps w/bolts. South Alabama.$100.00.

    Neil H.. Alabama.. '78 K5 400ci 4x4 AT,AC,PW Cheyenne. '74 C10 3spd/floor 250ci 4x2
     
  8. BorregoK5

    BorregoK5 1/2 ton status

    Joined:
    Sep 7, 2001
    Posts:
    2,457
    Likes Received:
    0
    Location:
    San Marcos, Ca USA
    I just picked up a 1978 K5 Blazer 400ci Cheyanne which was someone elses project, I assume. I've been trying to back track what is stock and what is not. The front axle is a Dana 44 and the rear a corporate 12 Bolt. Does this sound like stock as far as you know based upon your truck or someones previous swap? P.S. Great news on the 2 bolt mains, I'm it the process of building a 415 via Speed-O-Motive 400-415 stroker kit.

    &lt;b&gt;"What, Me Worry?&lt;/b&gt;
     
  9. Neil

    Neil 1/2 ton status

    Joined:
    Jun 10, 2001
    Posts:
    275
    Likes Received:
    0
    Location:
    Dothan,Alabama
    The 12 bolt and Dana 44 are stock equipment. What kind of goodies are in the 415? Sounds cool!

    Neil H.. Alabama.. '78 K5 400ci 4x4 AT,AC,PW Cheyenne. '74 C10 3spd/floor 250ci 4x2
     
  10. BorregoK5

    BorregoK5 1/2 ton status

    Joined:
    Sep 7, 2001
    Posts:
    2,457
    Likes Received:
    0
    Location:
    San Marcos, Ca USA
    Thanks for the axle info! The stroker kit has quite a few options from mild to wild. I've opted for the 9.0:1 ceramic coated hyperuetectic pistons, moly rings,radiased and polished heat treated 5140 steel crank, 400 flexplate and the external balancing, details at http://www.speedomotive.com/415maxi.htm . I didn't want the stock harmonic balancer so I sent them a 400 Fluidamper for the balancing. Initially, I was concerned with the 2 bolt main block I'm using but given that it wont see over 6000 rpm or more than 700 hp I should be good. I've ordered a set of Edelbrock Perfomer 64cc large valve heads and I'm working on finding a good multipoint fuel injection unit that can handle 1000cfm and up to 600 hp without breaking the bank. They advertise 500hp and 500flb of torque (380 flb torque at 2000 rpm) from a 500lb small block. Further research into those who have built them shows this can be done with a fairly mild breathing engine with hydraulic lifters and a non roller cam (I'm going roller for the smooth power band). My block is in the machine shop right now getting bored 0.30 over and arp steel studs on the mains and head bolts. I'll post more as it comes along.

    What, Me Worry?
     
  11. Neil

    Neil 1/2 ton status

    Joined:
    Jun 10, 2001
    Posts:
    275
    Likes Received:
    0
    Location:
    Dothan,Alabama
    Broh....that all has to be hard on the wallet!!!!!!!!!! Sounds like you know what you want out of this powerplant.

    Neil H.. Alabama.. '78 K5 400ci 4x4 AT,AC,PW Cheyenne. '74 C10 3spd/floor 250ci 4x2
     
  12. 502Burban

    502Burban 1/2 ton status

    Joined:
    Jun 8, 2001
    Posts:
    379
    Likes Received:
    0
    Location:
    Southern California
    Not that you sound as if you need reassurance from me, but I can tell you from experience that you will love that engine! A good friend just finished a '69 Camaro project with that Speedomotive 415 kit. We just did a track tune day with it at Willow Springs Raceway, and everybody there was freaking at how fast that car was going down the front straight.

    It's a dream to drive; a lot like a small big block, but without the weight. BTW, we had the car run on a chassis dyno: 500hp and 450 lb/ft of torque at the rear wheel. All this with shifting at or below 6,000rpm, and a fuel injection system that wasn't completely dialed-in yet. I'd love to get it back on the dyno now that I've got the DFI computer better sorted out.

    Check it out if you like at: <a target="_blank" href=http://www.pro-touring.com/featured_cars/Camaro/craig_boones_69_camaro/craig_boone_001.htm>Craig's '69 Camaro</a>.

    Robb
    '73 GMC Suburban - 502DFI
    <a target="_blank" href=http://community.webshots.com/user/robbrj>community.webshots.com/user/robbrj</a>
     
  13. BorregoK5

    BorregoK5 1/2 ton status

    Joined:
    Sep 7, 2001
    Posts:
    2,457
    Likes Received:
    0
    Location:
    San Marcos, Ca USA
    That 69 Camaro looks great 502Burban, I just sold my 68 327 Camaro last year which the 400 I'm building now was originally intended for. Thanks for passing on the link and info. I've had some theories on how much this motor would actually put out at the rear wheels and I think you've just confirmed it! I'll bet you a fully stock setup with this stroke kit could still put out some impressive numbers for those looking for a budjet powerhouse.

    What, Me Worry?
     

Share This Page