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How much will Power Pack heads improve a 283?

Discussion in 'The Hokey Ass Message Board' started by poboyross, Mar 21, 2011.

  1. poboyross
    Joined: Apr 29, 2009
    Posts: 1,839

    poboyross
    Member

    I know it's likely a broad and vague question...but I'm looking for a general answer beyond "Yes". lol. Here's my engine specs:

    65 283 from an Impala...nothing special
    500cfm Edelbrock carb
    Performer intake
    points distributor
    mild freshening.....new gaskets, lifters, rods. Cam looked good
    very mild honing on one cylinder to get some minor rust scale off
    backed up by a th350 and 81 Trans Am rear.... 3.08 ratio


    I got ahold of another 283 with the Power Pack heads, and was wondering how much more get up and go this might impart to my meek little engine? I'm running it in my 50 Chevy 2dr sedan. It doesn't have a whole lot of low end power, though.
     
  2. roughneck424
    Joined: Jan 10, 2009
    Posts: 1,049

    roughneck424
    Member

    Last edited: Mar 21, 2011
  3. poboyross
    Joined: Apr 29, 2009
    Posts: 1,839

    poboyross
    Member


    Great info..thanks! That makes sense about the rear end gearing. You can get a kit for what, 200 bucks? I'm not accomplished enough to swap them out, though.
     
  4. TexasHardcore
    Joined: May 30, 2003
    Posts: 4,724

    TexasHardcore
    Member

    What heads do you have now? They might be better than the PP heads.

    As for the rear gears...you say it's a '50 Chevy...but what rear end are you running out back? I'm guessing it's not the stock '50 torque tube rear...
     
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  5. poboyross
    Joined: Apr 29, 2009
    Posts: 1,839

    poboyross
    Member

    Stock heads that came with the motor....no power pack triangle, no humps, no nuthin' XP

    81 Trans Am posi disc rear....3.08 gears I believe.
     
  6. 56sedandelivery
    Joined: Nov 21, 2006
    Posts: 2,442

    56sedandelivery
    Member

    Another thing to consider might be to use 305 #601 heads with 53cc chambers; same valve size as Power Pack heads, probably a touch larger ports, and hardened seats. The HO #601's had 1.84 intakes however. IF you could find a good used set, and just clean them up, maybe cut the surfaces a bit to add a little compression with them. Most guys throw away 305 heads. BUT, you'll still benefit the most from gearing, and 3.08's just are'nt going to cut it. Butch/56sedandelivery.
     
  7. davidbistolas
    Joined: May 21, 2010
    Posts: 962

    davidbistolas
    Member

    poboyross- pull a valve cover and read out the casting numbers... from both the car and the extra motor...
     
  8. TexasHardcore
    Joined: May 30, 2003
    Posts: 4,724

    TexasHardcore
    Member

    The stock '65 heads are most likely better heads than the PP's. Post up the casting numbers and you'll have a definite answer.

    I have the same basic rear in my '56 F100. It's a '77 Seville Disc rear with 2.94's. It's fine around town with a stock 305 and TH400, but since I spend most of my time on the highway, it's not going anywhere. Later I'll do an engine swap and a 6spd with some 3.73's.
     
  9. poboyross
    Joined: Apr 29, 2009
    Posts: 1,839

    poboyross
    Member

    So replacing the rear end gears is a big hootenanny, no? I see sets on Jegs for under $200....some elsewhere for right around $100 or so. What all do I need? I'm going to assume that since I don't have a press or other fancy machinery that I'll likely need to find a shop to do it?
     
  10. HEATHEN
    Joined: Nov 22, 2005
    Posts: 7,585

    HEATHEN
    Member
    from SIDNEY, NY

    All 1965 passenger car 283s came with power pack heads, even the 195 hp 2 bbl engines. The only '65 283s that came with the heads with the rectangular block symbol on the end of the castings were truck engines. A pair of power pack heads will raise the compression over those heads, nothing more; same port sizes, same valve sizes.
     
  11. gas pumper
    Joined: Aug 13, 2007
    Posts: 2,786

    gas pumper
    Member

    3:55 is the gear for a 283 in New Jersey. Low enough to get out of it's own way and high enough for the Interstates.

    3.08 was the factory gear in the 60's NJ for powerglide cars. A 283 with a 2bbl could go as fast in low as in drive. They didn't have the power to go over 80 mph in high.

    Try Denville Transmissions and tell them you're a hamber.

    I'll take them PP heads off your hands, PM me if you want to sell local. Hey, I'd even be interested in the old heads with out the triangles.

    frank
     
  12. Rex Stallion
    Joined: Oct 7, 2007
    Posts: 590

    Rex Stallion
    Member

    When I had the 283 for our truck built, the machinist used 1.84 valves in the stock heads and put in hardened seats. Worked real well !!! With the smaller bore, you are limited on your choice of heads. On another 283 I had many years ago, it was bored to .125 over so I was able to use heads with .194 valves and a larger chamber. Lots of fun, they screamed!:)
     
  13. poboyross
    Joined: Apr 29, 2009
    Posts: 1,839

    poboyross
    Member

    What do you think is a good ballpark figure for them to do something like that? Me providing the gears, of course.

    I'll let you know if I sell those heads. I'm still trying to decide what to do with the engine that's attached to them...it's got 3 seized cylinders where the intake gasket blew. It's either that or the running 305/PG combo I've already got....don't think it'll be a had choice...but I love dem 283's! I might be willing to trade for some A parts. PM me if you want.
     
  14. Bored&Stroked
    Joined: Jan 14, 2005
    Posts: 2,901

    Bored&Stroked
    ALLIANCE MEMBER

    It all depends what you're looking for! The heads will probably NOT make much difference, unless somebody put a lot of work into them. Bottom line, you have a small cube, probably low-compression motor . . . not much bottom end to be pushing those gears.

    Three things stick out in my mind (if all the parts you have are good):

    a) Change the gears to something around 3.50 - this will definitely help out in the low-end and get the 'sled' moving a bit better. Now if you want to run at 80 MPH all day, not such a good choice - but probably a much better all-around choice.
    b) Change the cam to a 'Performer' type cam - that is designed for low-end torque and doesn't have a high RPM power-band. The classic '3/4' type cam.
    c) Don't know if you mentioned headers, but a great exhaust system always helps.

    There yah have it! One goofy ass HAMBers opinion . . . for what it is worth!

    B&S
     
  15. Vandy
    Joined: Nov 15, 2009
    Posts: 368

    Vandy
    Member
    from L.A. Ca

    Going to the Power Pacs is about a 40 HP improvement when used with a 4 bbl carb. Yes it makes a big difference. Upping the intake valve size as mentioned to the 305 HO intake is also a good upgrade, but I would do that when doing a full rebuild.
     

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