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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: 2,133


    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 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: 1,084


    Last edited: Mar 21, 2011
  3. poboyross
    Joined: Apr 29, 2009
    Posts: 2,133


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

    As for the rear 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: 2,133


    Stock heads that came with the 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: 4,204


    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


    poboyross- pull a valve cover and read out the casting numbers... from both the car and the extra motor...
  8. 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: 2,133


    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?
    Joined: Nov 22, 2005
    Posts: 7,594

    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.
    falcongeorge likes this.
  11. gas pumper
    Joined: Aug 13, 2007
    Posts: 2,925

    gas pumper

    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.

  12. 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: 2,133


    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'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: 3,843


    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!

  15. Vandy
    Joined: Nov 15, 2009
    Posts: 368

    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.
  16. Lcats
    Joined: Mar 17, 2008
    Posts: 80

    1. A-D Truckers

    Vandy - I have a 283 w/ PP heads and a 2 barrel carb. I need to do leaking gaskets all around - pan, timing etc. at this point- would you say a Comp cam 260H and a performer intake, 600 cfm carb w/headers be good to run with - I just want a cruiser, with some pep to get out of my own way (49 Chevy 3100). Thanks. Also, this motor was purportedly rebuilt -
  17. aaggie
    Joined: Nov 21, 2009
    Posts: 2,453


    Sounds like you have a run of the mill Chevy 10 bolt rear end. Shop around the Pick-A-Part yards and find a complete rear end with lower gears and swap out the whole unit. It might be cheaper than replacing the ring and pinion.
  18. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,178

    Bruce Lancaster

    283 with high rear gears is likely worst problem here for performance, and with the high gearing much normal souping like hot cam, better heads, etc. won't help much because car will seldom be able to get into RPM level where the mods help, AND will spend most of its time at low chug where all mods except more displacement and compression actually hurt performance. In the heyday of the 283, the big decision was between 4.11 and 4.56, which says a lot.
    Dropping rear gear of course costs a lot and will also raise cruising RPM while helping at low speed.
    Assuming you aren't rich just yet I would plan this as a staged build, with one stage being low cogs 3.70--4.11 range, other stage being a 200 R4 with an overdrive and lockup...OR more Hambish and more better, do the stages as an evolution to trad 283ness. Keep your eye on the want ads on HAMB for a '55-7 Chevy rear or even classier '57 Pontiac, keep hunting for a drop-in with suitable gears, then a stick trans...(an automatic 283?? Horrors!).
    An old 3 speed with OD would be best traditonal spread, four speeds won't help cruise...unless you can dig up bits needed for a hybrid Saginaw 4 with OD transplanted from Saginaw 3 speed...
    A modern OD 5 speed of course would be perfect though out of 283zeit.
    THEN you have to add in some compression and an 097 cam, which accomplishes the proper gentle clatter of a hot 283.
    And remeber, the traditional goal of all 283 owners was once upon a time coming up with the bread for a CSC 3.5 inch stroker crank and bore job to 4.00 for the traditional KILLER 352. At that point, tradition requires you to give the Duntov to a kid and swap for a 30-30 cam...sound effects MUST be correct at any stage of 283 development.
  19. porknbeaner
    Joined: Sep 12, 2003
    Posts: 38,219


    You will be when you are done. :D

    I unlike many others on the board like power pac heads. I can't tell you how much it will wake the engine up but they are an improvement over standard 2 bbl heads if that helps. They will probably work well with your combo.
  20. 50 customcoupe
    Joined: May 8, 2011
    Posts: 342

    50 customcoupe

    I agree with Beaner. I have a '50 chevy coupe with a '64 283 with PP heads, 2 bbl, dual exhaust (no headers), '64 powerglide, and a '55 chevy rear end with 3.36 gears. Car has good take-off at red lights and will run the inter-state at 75 to 80 very easy at a decent RPM, I am very pleased with the performance.
    luckythirteenagogo likes this.
  21. i hope after 4 years the OP has it figured out....but in case he hasn't here is my opinion: they will add at least 200 HP and being able to say you have Power Pack heads will improve your love life
  22. porknbeaner
    Joined: Sep 12, 2003
    Posts: 38,219


    I like a 3.26-3.55 gear for my bigger engines but on a 283 I really like a 3.55 for a tall gear and as deep as a 4.56 ( like Bruce suggested) for a deep gear. I can see a gear between a 3.36 and 3.55 being a good driver gear especially if it is a way between towns. ;)

    it is a shame that most of us can't just set down and build an entire car but most of us is we did we would never drive one stages as has been suggested is always a good option.
  23. alphabet soup
    Joined: Jan 8, 2011
    Posts: 993

    alphabet soup

    305 H.O. heads work really well on a 283. A few years back I built a 283 for my buddy's '59 Chris Craft boat. It acted like a different boat with the 305 heads. Granted, the 283 that was in it was a little tired. But the difference was crazy. The two motors had the same basic cams, compression, intake and carb. I too think you could use a little more gear. I would be looking at 3.55's.

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