average cost to rebuild 350 short block

Discussion in 'Engine Topic' started by GM72_SuperSport, Jun 5, 2010.

  1. GM72_SuperSport

    GM72_SuperSport Veteran Member

    May 31, 2010
    I have a friend who recently blew his stock impala engine and I've never gotten an engine rebuilt and I wanted to know how much that usually goes for? Machine work and parts. Remember its a stock rebuild not a street performer. Thanks guys
  2. AJ_72

    AJ_72 Veteran Member

    Jul 3, 2003
    Chebanse, IL USA
    If you really want the basic of the basics, get a reman or a replacement crate engine. Comparatively speaking, you can't beat the warranty you get with most reman engines. Machine shop rates are not cheap.

    Just for reference... 10 yrs ago I had a block bored .030" over and the crank ground down .010" on the mains and rod journals. The block was "checked over" after being power blasted (flat decks, reinstall cam bearings and plug all the holes after the overbore). But other than those things, it cost me ~$500. That's not including the parts I bought, but have yet to assemble (pistons, rings, bearings, gaskets, fuel pump, oil pump, etc.). Plus the heads haven't been tended to, yet.

    The parts alone (in a basic rebuild kit) were ~$450. If I could do it over again, I'd just flop down the money for a rebuilt or replacement engine.
  3. cmonson

    cmonson Veteran Member Gold Member

    Apr 7, 2006
    Calgary, Alberta
    for a stock replacement motor, you can buy a crate for $1500 or even less:


    Depending on what is involved it is often cheaper to go crate. If you are only doing a basic re-bearing / ring job / valve job, you may consider a rebuild. That said, you won't get a warranty on your own rebuild...
  4. cmonson

    cmonson Veteran Member Gold Member

    Apr 7, 2006
    Calgary, Alberta
    also, consider buying a used motor if this is just a DD. You ca probably hunt down a used basic engine for $500.
  5. muscl car

    muscl car Veteran Member Lifetime Gold Member

    averages out to about $1k per 100hp
  6. Knuckle Dragger

    Knuckle Dragger Administrator Staff Member Lifetime Gold Member

    Nov 2, 2002
    Waddell AZ
    You need to shop around if that's what you pay.
  7. Todd80Z28

    Todd80Z28 Moderator Staff Member Lifetime Gold Member

    Jun 11, 2002
    Northern VA
    I'm stewing on this now, looking for a low-budget way to stop the "Gulf oil spill" that is my rear main seal leak.:)

    Overall, it looks like a typical replacement short block will be within $200 of very BASIC machine work. You can get a new GM 350 (L31) one piece short block from sdparts.com for $1200. Ebay has several in the $1600-$1800 range with new crank/rods/pistons. I don't think I'll save much getting new pistons stuffed into my factory 1980 setup.
  8. mrvedit

    mrvedit Veteran Member

    Jun 12, 2009
    Ann Arbor, MI
    I agree with AJ_72 - think "Crate motor" or a used engine on Craigslist. A re-build kit is $500, another $500 for machine shop work and then labor/time to rebuild it. If the engine was "blown" then you also need to replace any broken parts; it is very possible that the block was damaged beyond repair.
  9. Cardinal

    Cardinal Veteran Member Lifetime Gold Member

    Jun 22, 2003
    Endicott, NY
    When you say your friend "blew up the motor in his Impala", explain what "blew up" means: spun a bearing? timing chain blew which wiped out the valves/heads? or a DEAD engine = connecting rod(s) hanging out the block?

    If it's the last senario (rod hanging out the block) you now have to find a replacement short block or complete engine to rebuild which adds to the cost of the rebuild. IF you were lucky enough to find a plain jane 350 SBC that needs to be re-ringed, new bearings, no crank work, then a engine rebuild kit from Northern Auto Parts + the "new" engine would cost under $500 + the cost of freshening up the heads. The short block would need to be in great shape (not boring required) to keep it that inexpensive.

    IF the "new" engine needed to be bored that would cost around $150 for eight holes. BUT the machine shop will want to have a clean block to work with ($100 including installing new cam bearings and frost plugs) + about another $100 to hang the new piston onto the old rods. A GOOD machine shop will want to recondition the old rods by magnifluxing, shot peening, resizeing, and new high strength rod bolts which would cost around $150. Plus they'd probably want to measure the crank which would probably lead to them turning the crank for around another $150. All of the above numbers may be high or may be low depending on the machine shop's prices. ASSUMING that I'm not to far off on the prices, it is going to cost somewhere around $1000 (machine work + rebuild kit but probably not including the cost of the replacement engine).

    Realistcly, buying a basic Targetmaster is more cost effective if you don't have an enigne to rebuild and the Targetmaster has a warranty (which USUALLY a machine shop won't guarantee an engine that they rebuild).
  10. KansasTwister

    KansasTwister Veteran Member Lifetime Gold Member

    Oct 7, 2006
    Lawrence, ks
    im looking into the gm zz4 350 shortblock for my build, the lt1 block didnt work out sadly. Plus 11:1 on todays gas would have made the car udnesirable to drive on the street.

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