1981 Z/28 Speed Secrets Needed

Discussion in 'Camaro Questions' started by 70-SS/RS-L78, Dec 24, 2016.

  1. 70-SS/RS-L78

    70-SS/RS-L78 Veteran Member Lifetime Gold Member

    Mar 19, 2003
    Phila area
    I recently brought a 1981 Z/28 and I am not real thrilled with the performance of it. I owned one way back when in 1984 and it was stolen before I had a chance to wake it up, I was going to Turbocharger the car. before some low life stole it. Hear is my dilemma, I wanted an 81 but all of the cars I looked at were hacked or were full of rust worms. I wanted a super clean White or Silver Z/28. This car is beautiful shape and was cared for so I really don’t want to do anything to this car that does not look like it belongs, I’m not looking for a 12 second car just something that will get out of its own way and not get passed by an Ecoboost Ford Taurus, I think the exhaust will be the first thing changed so I will just store the original system if the next owner wants to put it back on. I was also thinking about putting a 2004R trans in the car to help her along. If anyone knows how I can put some pep in this old girls step I would appreciate your input. The car is a 350 with Automatic. Thanks....



  2. loyal guardian

    loyal guardian Veteran Member

    Aug 28, 2013
    helena mt
    you want something kinda zippy but still look stock when you pop the hood, do a remote turbo setup (or twin turbo). you can use headers and an x pipe and have the turbos in the back. youll have to rebuild the engine to handle it but you can keep it looking stock.
  3. 80sz

    80sz Veteran Member

    Feb 2, 2014
    I'd do a cam swap and be done. The motor will really wake up and the stock 3.08 gear will be fine. Overdrive is great ,unless you're driving cross country the 3 speed would stay for me. Clean car ,I like.
  4. BonzoHansen

    BonzoHansen Administrator Lifetime Gold Member

    How original is it under the hood? Is it still running a computer?

    The car is beautiful
  5. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

    Feb 26, 2004
    Bloomington, MN
    Does it have A/C?
    That really limits the space under the hood for a turbo.

    A little more aggressive cam, a 2004R (or 700R4) and a set of 3.73-4.10 gears (with posi) will get it out of the hole quite nicely without changing your highway cruise RPM too much or being very noticeable as "not stock".
  6. 70-SS/RS-L78

    70-SS/RS-L78 Veteran Member Lifetime Gold Member

    Mar 19, 2003
    Phila area
    I was thinking about putting a warmed over small block in the car and bolting everything back and putting all of that spaghetti back on the new engine. The computer is hooked up and working, The car has a Virgin engine compartment, It has never been touched and still has the original spark plug wires and hoses, I am going to flush the cooling and brake system tomorrow while I am hiding from the family. A friend of mine stopped by last night and we were having a few cocktails while looking the car over and let me tell ya he really broke my 8alls about messing with this car. I need to find a way to motivate this car somehow without screwing it up.:( Hear are a few under-hood pics.


  7. czizza

    czizza Veteran Member

    Jan 8, 2004
    N. Massapequa, NY, USA
    For about 2K:
    If you intend to keep it then go with an Edelbrock Performer RPM upgrade (CARB, CAM, Manifold and 66cc Heads) it should give you about 100 more horses.

    For about 1K:
    If you want to do it cheap go with a Performer RPM manifold, Holly 650CFM and Nitrous.

    For over 2K:
    If you want to do it right then go with a new engine solution there are many. The reason I state this is the old 350 you have is a 2 bolt 8:1 Engine if you do the Edelbrock RPM heads at 66cc you will push the C/R to 9:1 good but still not enough. The 2 bolt will last but you will be replacing it soon.
  8. BonzoHansen

    BonzoHansen Administrator Lifetime Gold Member

    you have to decide how much you are willing to change under that hood. I'm usually all for changes, but if that car is 100% original it will be had to make a lot of changes. Its only original once. I'd be hard-pressed to change much of anything.

    There are ways to keep everything and make some minor changes. They makes CCC friendly cams, better heads and intake. There are updates to that carb available. Exhaust can be removed and stored.

    If the car isn't get driven much, gears are also a good option. 3.73s will really light it up.
  9. larrylarry

    larrylarry Veteran Member

    Dec 22, 2011
    San Antonio Tx
    TH200r4 & 2200 stall torque convertor & 3.73 or 4.10 gears, no one would ever know. I have a TH700r4 in in my 78 but hind sight being 20/20 I should have went with a 200r4 because of the first gear ratio in a 700r4 but otherwise than that my 700r4 is great. A vast improvement over a TH350 plus a 200r4 & 700r4 can tame the rpm's at highway speeds with 3.73's & 4.10 gears. With those gears a TH350 will be at 30 to 3200 rpm's @ 70mph where a 200 or 700 will be at 21 or 2200 rpms. The reason for a 2200 stall torque convertor is if these is just a weekend diver car you don't need a higher stall convertor. If you do go with a 200r4 or 700r4 you should go with something with some beef in it, stronger than normal, like a stage 1 or 2 transmission. My 700r4 is more like a stage 2+ but it shifts between gears normal & smooth when driving normal but when I hammer the go peddle it will shift hard. Doing a rear end gear change with the above transmissions & torque convertor you WILL feel a big difference.
    And no one will ever know!
  10. 70-SS/RS-L78

    70-SS/RS-L78 Veteran Member Lifetime Gold Member

    Mar 19, 2003
    Phila area
    Today we changed the Brake,Cooling and trans fluids and flushed the systems, We were bouncing ideas around all day long and one thing is certain; Getting this car to hang with today's muscle cars and keeping things intact will be tough, A 3.73 gear change and a 2004R will definitely wake it up, But before that is done I have to look into how this stock Carb/Computer system works and if it is possible to fatten it up plus a 100 shot of giggle gas would not harm the engine if done right. Then we are upgrading the fuel system to keep from harming anything and these changes are easily reversible. This car truly is a survivor so I don't want to be the IDIOT who screws it up.:(

Share This Page