Register now to get rid of these ads!

how to tell a 350 & a 327 apart?

Discussion in 'The Hokey Ass Message Board' started by turdchazer, Dec 6, 2008.

  1. turdchazer
    Joined: Dec 4, 2008
    Posts: 644

    Member Emeritus
    from Spokane

    What are some of the tell tale signs, besides a block stamping , that says this engine is a 350 or is this a 327
  2. dudley32
    Joined: Jan 2, 2008
    Posts: 2,158


    327 always has a valley vent at the back of the block just behind the intake manifold so does a 283...
  3. Deuce Roadster
    Joined: Sep 8, 2002
    Posts: 9,519

    Deuce Roadster
    Member Emeritus

    True ... but so does the 1967 Camaro 350 block. It is a one year deal but they do exist.
  4. Von Rigg Fink
    Joined: Jun 11, 2007
    Posts: 13,426

    Von Rigg Fink
    from Garage

    I think the only way to tell for sure is the stamped numbers on the pad in front of the passenger side head.(on the block).that is with out taking it apart..

    squirrel! out there?

  5. dudley32
    Joined: Jan 2, 2008
    Posts: 2,158


    to deuce roadster...
    ok ...realy?...I didn't know that... wonder why they would revert back? to relieve pressure? info thanks...
  6. 32Rules
    Joined: Mar 17, 2007
    Posts: 202


    1968 and 1969 327's did not have the crankcase vent cast into the block. My 67 Pace Car had the correct 350 with crank cas ventilation cast in block. Only year for that ona 350. 327's were phased out for the new yuk 307 in 1969
  7. balancers are different,flange on crankshafts are different,casting #'s
    Joined: May 23, 2005
    Posts: 4,407

    Alliance Vendor
    from AUSTIN,TX

    some 327's also do not have harmonic balancer bolts. I don't know what years that is or is not specific to, but I do know it's not like that on chreefiddies.
  9. OldSub
    Joined: Aug 27, 2003
    Posts: 1,064

    Member Emeritus

    Measure the stroke. If the stroke is 3.25 its a 307 or 327. If its 3.48 its a 350.

    So many of the small blocks available have been built from collections of parts that I'd be cautious of trusting any external sign that isn't a measurement.
  10. Actually the 283 was phased out in late '67 for the 307 that came out in '68 models. The 327 was phased out in '69 and it's replacement was the already available 350.

    As far as breather tube in 1967 350's...... very true (one year only block). No breather tube in 68-69 327's and journal size also increased as GM was tooling up for the swap over to the 350.
    Deuces likes this.
  11. squirrel
    Joined: Sep 23, 2004
    Posts: 52,786


    To be sure, measure the stroke...for clues, look for the small damper, draft tube hole, valve covers with the little rectangle in the middle, etc.
  12. To the best of my Knowledge all 327 blocks have a small Vertical web on the Front of the block inboard of the Passenger side water pump mount flange next to a 1/8" pipe plug. No 350 blocks have the web or plug. Also the distance between the pump flange and the Web is different between 283 and 327.
    The Wizzard
  13. squirrel
    Joined: Sep 23, 2004
    Posts: 52,786


    this rib?

    Attached Files:

    • 327a.jpg
      File size:
      47.4 KB
    • 327b.jpg
      File size:
      32.4 KB
  14. That would be Correct. To the best of my Knowledge "no" 350 has that rib. Also the Grove is wider on a 283 than a 327. You can feel it with your Finger when they are side by side.

    The Wizzard
  15. Terry
    Joined: Jul 3, 2002
    Posts: 1,825


    That's the way I was taught too.

  16. HRK-hotrods
    Joined: Sep 26, 2007
    Posts: 922


    Just an FYI, the 307 wasn't available in a Camaro until midyear 69'. It replaced the 327 as the base V8...

    As far as the 307 being a YUK motor, have YOU ever had the pleasure of playing around with one? They are GROSSLY underestimated. With a 283 bore and a 327 stroke, they put some pretty good horsepower/torque out for the size and they're good on gas too... They rev quick and have a strong bottom end... Change the heads, put in a better grind cam and you got something;)
  17. conn.rod
    Joined: Nov 29, 2006
    Posts: 60

    from atlanta

    check the casting numbers on you can ck small and bbc block and head castings
    razoo lew likes this.
  18. Grumpy Ed
    Joined: Mar 21, 2017
    Posts: 4

    Grumpy Ed

    You are right on with the 307. I had a 71 Nova with a 307, added a set of Double Hump heads (1.94) and a mild cam with a Holley 600 and Edelbrock Torker intake, headers, and that car woke up. Put a shift kit in the Turbo 350 trans also.
  19. samurai mike
    Joined: Feb 24, 2009
    Posts: 535

    samurai mike

    what are you talking about? a 350 buick and a 327 packard look nothing alike!
    54vicky likes this.
  20. Anorexicvega
    Joined: Jan 13, 2017
    Posts: 2


    The 67 350 and 302 has the rib and plug. The 68 may have them too.
  21. 56sedandelivery
    Joined: Nov 21, 2006
    Posts: 6,695

    Member Emeritus

    Lots of large journal 327's were built using 350 blocks, especially the 4 bolt blocks. The compression height of the piston (1.67 for a 327; 1.56 for A 350), or the casting number on the crankshaft should tell you what it actually is.
    I am Butch/56sedandelivery.
  22. rudestude
    Joined: Mar 23, 2016
    Posts: 2,991


    Just thought I would throw this info in...its from the How to Hot Rod Small-block Chevys....HP Books 20190228_235541.jpeg 20190228_235510.jpeg 20190228_235500(0).jpeg 20190228_235439(0).jpeg 20190228_235434.jpeg 20190228_235401.jpeg 20190228_235333.jpeg 20190228_235306.jpeg 20190228_235231.jpeg

    Sent from my SM-T387V using The H.A.M.B. mobile app
    tb33anda3rd and Deuces like this.

Share This Page

Register now to get rid of these ads!


Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.