882 to 186 heads. Any gains?

Discussion in '1970 - 1973 Specific' started by Bob1970sbc, Feb 22, 2018.

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  1. 70lt1z28

    70lt1z28 Veteran Member Gold Member

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    Beavercreek, Ohio, USA
    Keep in mind these heads did not have hardened exhaust seats, so not the best for no-lead gas. Folks use them and they will work, but if you are going to put a bunch of miles on them the seats will erode.

    If it isn't a "numbers matching" thing which it sounds like it isn't, you may be best served to eBay them as they do have pretty good value to those restoring. Probably could take the dough and just about get a set of fully prepped aftermarket aluminum heads. Something to consider.
     
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  2. Bob1970sbc

    Bob1970sbc New Member

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    Feb 22, 2018
    Yes. I was considering posting them for a few weeks. If they don't sell I could bolt them on when the weather is nice
     
  3. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

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    I think selling them is the route to go. Unless you're strapped for money and time, don't get in a hurry to sell them. A set of assembled Edelbrock Performers are around $775 now, just try to stay with the USA made stuff.
     
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  4. Bob1970sbc

    Bob1970sbc New Member

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    Feb 22, 2018
    I don't want to put the money in aluminum heads right now. The 882's that are on it work fine. Guess I'll try to resist just bolting them on for a little increase in performance and get them sold. Aim for better in a few months
     
  5. G72Zed

    G72Zed Veteran Member

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    Canada
    Bob1970sbc, Read the posts and ran the #'s provided. They way I see it, in a nutshell, the stock 882's with 76cc chambers flows approx. 205cfm with 1.94 (according to data), the Comp Ratio with a stock bore 350/Flat tops set up is approx. 8.9 comp. ratio.

    The stock 186's with 64cc chambers (according to data), the 1.94's flow approx. 215cfm, same stock bore 350/Flat Tops comp. ratio comes in at 10.08.

    It's most likely a little less on both if you factor in actual piston to head clearance & ring land HG crevice volumes and actual true valve relief cc's. Basically, -12 cc is 1.18 points in CR. Looking at the possible +10cfm of the 186's, may get you another 15-20hp (21.3hp using the hp/CFM formula).

    I would do a cranking compression test to see where your at with the 882's, that may indicate and give you a rough indication if you will be able to tolerate the extra point in CR.

    Again, just my $0.02. Good luck whatever you decide.
     
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  6. Lowend

    Lowend Administrator. .a car, a man, a maraca. Staff Member Lifetime Gold Member

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    I'd dump the 182's to someone who wants to do a matching #'s restoration.
    For the effort, there just isn't much gain to be had.

    A set of 3.42 gears (stock ratio easy to match to speedo) and some ignition/carb tuning will get you more drivability with less effort.
     
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  7. Bob1970sbc

    Bob1970sbc New Member

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    Feb 22, 2018
    Yeah. I grew up with a certain nostalgia for the old double hump irons. Had a buddy in high school that would out run plenty of fox bodies in a Impala 327 with humps. I know there is a lot better heads out there. I probably don't put a hundred miles a month on the car and only run the 93 no ethanol.
     
  8. Bob1970sbc

    Bob1970sbc New Member

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    Feb 22, 2018
    Yeah. It's a 70 so 8.2. So the 3.36 would be the equivalent to 3.42's I guess. At least that's the kit I was looking at
     
  9. Bob1970sbc

    Bob1970sbc New Member

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    Feb 22, 2018
    Weather is bad here. So no breaking into engines. I'll post the heads until better weather. Any good sites besides E-Bay?
     

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