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Building a 383

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by bigwheels6, Jul 22, 2001.

  1. bigwheels6

    bigwheels6 Registered Member

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    On the way back from the coast last night my tired old 350 started smacking a rod into the block (I believe). I think it's time to build the 383 I've been thinking about, but I haven't fully researched it yet. I specifically am interested in the Summit kit, but I don't know about all of the necessary modifications to the block. Has anyone built one of these? I would love to hear what you have to say.

    In every contest there must be a loser.
     
  2. CaptCrunch

    CaptCrunch 1/2 ton status

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    Most times it works best to just get a short or long block kit for these unless you have a good in w/ a machine shop. The time alone at the machine shop for it and the price of prep work add up real fast so anything non-competition I would just get a kit already assembled. The last 383 this winter I was in on spent approx 50 hours in prep razoring the crank, balancing the the lower half, overboring and the notching out for the rods, etc. Then after this we still had to file rings and all that lame stuff, but this was a pretty extreme motor for racing and pretty much all the stops were pulled out

    -Mikey
    1987 Chevy K5 Blazer- 350 TBI
    <a target="_blank" href=http://www.geocities.com/milnerlives_2000/blazer.htm>http://www.geocities.com/milnerlives_2000/blazer.htm</a>
     
  3. michaelm

    michaelm 1/2 ton status

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    block mods are supposed to consist of notching the bottom of the bores to clear con rods, no?
    mock up crank and 1 con rod/piston at a time and grind till it clears enugh fer a full rotation. a little time consuming but doesnt sound to rocket scientist.
     
  4. bigwheels6

    bigwheels6 Registered Member

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    I was already looking at a kit from Summit. I figured the same way you did about the cash. I'm only looking for ~350 HP so the cast crank and hypereutectic pistons should be fine. I don't imagine going over 5500 RPM too often. I figure the parts won't go much over what a regular old 350 rebuild would be, given that my crank and rods are probably shot. The machine work is the variable though. If all that needs doing is clearencing the block, how many hours does something like that take? I've been through the rest of a buildup before, so I have a pretty good idea what to expect, but this degree of block prep is new. Exactly where is material removed from the block? Is it from the cylinder walls, main webbing, wall of crankcase? Anyway, if the cost looks to be beyond a BB swap, I may go that route.

    In every contest there must be a loser.
     
  5. muddin4fun

    muddin4fun 3/4 ton status

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    Machine work for building a 383 is EXPENSIVE! I looked into it. If I had built it even with a stroker kit, it was gonna be 4K by the time I got it built and ready to put in. So, I got a crate motor (waranty and all put together already). It was easier and cheaper. If cost is a concern and you aren't worried about customizing the crap out of it, go with a crate 383. Mine is a 375hp motor.

    I've got a mind like a . . . a . . . what's that thing called?

    <a target="_blank" href=http://www.geocities.com/muddin4fun79blazer/>http://www.geocities.com/muddin4fun79blazer/</a>
     
  6. Neil

    Neil 1/2 ton status

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    Man!! If all you need is 350HP stay with a 355c.i. 350 HP is VERY obtainable from what ya got in your 350. A 350 motor needs a strong bottom end and the right heads/valetrain,cam etc. Save the $$ and do it with .030 on your 350!! Been there, done that.I have built 350+ hp 350s before..dyno proven..

    Neil H.. Alabama.. '78 K5 400ci 4x4 AT,AC,PW Cheyenne. '74 C10 3spd/floor 250ci 4x2
     
  7. mudddog91

    mudddog91 1/2 ton status

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    Hey guy I just completed my 383 buildup using the summit 383 rebuild kit.I bought a speedomotive 383 cast crank brand new for 200.00 ,summit kit was 300.00 ,new summit stage 2 rods for 200.00,had it bored .030,balanced,and new cam bearings,I clearenced the block myself(can be done in about 2 days),put and edelbrock intake and carb and a set of dart iron eagle heads and ive got about 3500 in it but remember the heads were close to 1000.00 themselves so ...........
    IT WAS WORTH EVERY PENNY FOR THE AMOUT OF TORQUE PROVIDED JUST OFF IDLE!!!!!!!!!i DONT BELIEVE A 355 CAN PROVIDE THE AMOUNT OF TORQUE AT THAT LOW OF AN RPM........
     
  8. 84_Chevy_K10

    84_Chevy_K10 Banned

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    I too was going to build a 383, but my current 305 (yes, 305, no typo) has so much power that I'm not going to build it.

    If I were to build one, I'd use Vortec heads, a Performer RPM Vortec, hypereutic pistons, a good set of 5.7" or 6" rods, and a cast crank. Add a Comp Xtreme 4x4 cam, self alligning roller rockers, a good timing set, and ARP everywhere. Have lower end balanced, do the clearancing yourself, have the block bored .030 and have it checked for line boring, boil it and put it together.

    Tim
    '84 Chevy K10, lifted, loud, fast, and 3/4 ton axles
     
  9. BI U JIMMY

    BI U JIMMY Registered Member

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    That just described my engine almost exactly. I got my kit from speed-o-motive, had them balance the rotating assembly. I got the Vortec heads with the self aligning roller rockers, extreme 4X4 cam with performer intake and afterburner headers. I will fire it off this week so I will see if it will make the power I want
     
  10. CaptCrunch

    CaptCrunch 1/2 ton status

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    It is basically notching and clearancing the block. It really depends on what tools you have in regards to how long it will take. You can do that, but then will still want to go have it bored, checked for line hone, check for cracks, etc. and then cook it out. But it seems like a lot of work to save little money when you can get a 383 bottom end from numerous sources for about a grand...

    One word on the vortech heads... they will make a nice lower rpm 4x4 motor, but most 383's really like a bigger intake post... something in the 190 to 200 range apposed to the 170's in the Vortechs. Good heads in that aspect would be sportman II's , AFR 190's, and Brodix Track I's

    -Mikey
    1987 Chevy K5 Blazer- 350 TBI
    <a target="_blank" href=http://www.geocities.com/milnerlives_2000/blazer.htm>http://www.geocities.com/milnerlives_2000/blazer.htm</a>
     

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