383 Stroker? Engine rebuild

Discussion in 'Engine Topic' started by '71StreetZ, Oct 28, 2017.

  1. '71StreetZ

    '71StreetZ New Member

    Aug 18, 2017
    Hello all I have a 327 in my 71 right now which will need new piston rings soon as far as I can tell it’s a large journal 4 bolt main block but I haven’t cracked it open yet and I am deciding on whether or not to rebuild it with a 383 stroker crank and new lifters while I’m putting rings in it. Right now it is bored 0.060” over and has a Comp Cams hydraulic flat tapper cam in it Edlebrock rpm performer intake and aftermarket heads, the only down side I can see is having to buy a bigger carb. What do y’all think, anybody made a 383 out of a 327 before?
  2. biker

    biker Veteran Member

    Just built one out of a 350 roller cam block. Wasnt expensive, lots of info for whatever combo you want and absolutely rips. Just my opinion and most here would agree, but I would go with a roller cam based on reliability and power potential.

    CNC BLOCKS Veteran Member

    Oct 11, 2004

    Any .060 GM block should be sonic tested, I find very few that re safe for a performance build at .060. At .060 over plate honing is a must. If the block was bored off unsquared decks not much of a good job done by the shop.
  4. G72Zed

    G72Zed Veteran Member

    Sep 8, 2015
    I believe GM never made a 327 "4 bolt Main" block, they'r all 2 bolt mains, 62-67 small Journal, 68-69 large journal. If it's a large journal 4 bolt main, with a 3.250 stroke, it might have been rebuilt that way, see if it's a steel crank, fairly hard to get in LJ size, usually Vette's or trucks.

    Listen to CNC, and his recommendations closely, not fun dumping $$ in a block then finding out the weak spot.
  5. '71StreetZ

    '71StreetZ New Member

    Aug 18, 2017
    Wasn’t I’m the mid ‘90s that GM switched over to the roller cams? I have thought of buying a 350 block and just starting over
  6. '71StreetZ

    '71StreetZ New Member

    Aug 18, 2017
    thanks for the heads up!! the previous owner of the car could have been mistaken I haven't had the heads off yet to measure the bore, the motor was built by the local engine builders in Beaver creek Ohio and still has their serial number and name stamped into the factory stamping pad under the passenger cylinder head, tomorrow I will call them and see if they have any records on the car
  7. BonzoHansen

    BonzoHansen Administrator Lifetime Gold Member

    Mid 80s
  8. '71StreetZ

    '71StreetZ New Member

    Aug 18, 2017
    I got in touch with the builders of the motor its a 327 small journal car which i figured out from the casting number on the back side of the motor (listed below) but CNC was right its 30 thousandths over with a forged balanced crank and 2 bolt mains, still not a bad little motor but I think I am going to look into a 355 this spring.
    Casting Numbers
    Stamping pad under passenger side head
    Performance Clinic 00011712 (their serial number)
    Drivers rear
    GM 3858174 (64-67 327 2 bolt)
    Passenger rear
  9. Rdobbs1977

    Rdobbs1977 Huge Guns N Roses Fan

    Dec 1, 2014
    i built a 383 last year on a gen 1 68' 327. FYI, any 383 can be built from the 302, 327, 350 block as they all shared the base 4.00" cylinder.

    Not a fan of flat tappets when you've got rollers rolling around out there:)
  10. '71StreetZ

    '71StreetZ New Member

    Aug 18, 2017
    If I am not mistaken though 68 and later 327 Chevy blocks are the "large journal" 327 and share the same main and rod journals with the 350 where as my early 327 has 2.300" mains 2.000" Rods and the later blocks have the 350 with 2.450" mains and 2.100" Rods

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