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Quick help on 350 Heads

Discussion in 'The Garage' started by SHINTON, Aug 12, 2002.

  1. SHINTON

    SHINTON 1/2 ton status

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    My valve seats or something is leaking oil and blows smoke starting, up, etc. I found the following for sale CHEAP and want to make sure it will fit my engine.

    Here is a set of 350 Chevrolet heads. Heads are in good shape and come with valves, rockers, and valve springs. These are 882 iron heads and have 1.94/1.50 valves, 76cc chambers, and 160/60 intake and exhaust port volume. These heads would be perfect for a stroker due to the increase compression of a stroker engine.

    My Jimmy is a 72 with the 350 obviously. If I can buy these pretty cheap will it bolt on? If I pull my heads and replace with these what 'else' should I do while I am in there?

    Finally...am I wrong in thinking pulling/replacing the heads is a 'simple' bolt in/out project? Could be done with the engine still in the Jimmy? (Non daily driver, can be left 'as is' for periods of time, etc)

    Sam Hinton
     
  2. backyardbuilt

    backyardbuilt 1/2 ton status

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    Yes you can change them in the truck it isn't that hard just time consuming if you can get them cheap go for it they don't sound much different than a stock head from that year.
     
  3. Sandman

    Sandman 3/4 ton status Author

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    I changed mine out in the vehicle and lifting them out can be a real pain.
     
  4. SWAMPDOG

    SWAMPDOG Newbie

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    The 333882 heads came on 74 thru 80 350 and 400 engines. If you plan on doing in the truck take out the fender wells.You can sit on the front tires and do anything you want.It is only 5 or 6 bolts.It ain't to bad of a job that way.If your engine is tired you might just try to put in new valve seals ( smokes just a little when it first starts)instead of changing the heads.
     
  5. kennyw

    kennyw N9PHW Premium Member

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    The 882 casting will be a step backwards from your stock heads (performance wise). They are the most common heads available and basically smog heads with poor flow. You can have your stock heads rebuild reasonably if you shop around.
     
  6. Mr.Chevy4x4

    Mr.Chevy4x4 1/2 ton status

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    882's were some of the best flowing stock cast iron heads GM made until the Vortec's came out. They don't do much for compression because of the 76cc chamber, but they flow very well!

    Mike
     
  7. SHINTON

    SHINTON 1/2 ton status

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    My buddy was saying to just pull my heads and rebuild them as well. Course he was trying to get me to go ahead and find some vortech heads to put back in there and alum intake, get some extra hp.

    Basically ALOT of smoke when it first starts, and sometimes like if I am idleing in a drive thru it will start smoking. I have heard 'valve seats' before and also heard someone mention 'umbrella seals' as a fix.

    Can any of these be done with the head still on the block or should I really pull it and rebuild the 'right' way. The Jimmy has 172K on it, and never has been rebuilt as far as I know. (Good OLD GMC technology!!!!)

    Still strong as a horse, just finished doing a bunch of trails at Uhwarrie National Forest in NC on Saturday, the old girl still kickin some BUTT!!!! Course the guys in the XJ behind me were complaining bout BLACK LUNG from my exhaust...heh. I think that is mostly me running kinda rich and needing a tune up.

    I basically am planning on parking the Jimmy in September at my dads Garage, and we are gonna restore it this fall. New paint, Herculiner interior, and misc engine/brake stuff to get it back up to par.

    So pulling the heads and leaving off a couple weeks will be ok, is not my daily driver.

    Sam
     
  8. Sandman

    Sandman 3/4 ton status Author

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    I think that in '72 the heads did not have hardend seats yet. They might already be trashed. If this is the case you might as well get those other heads. If you put flatop pistons in you'll get around 9:1 which is a good all around compression. Talk to your machine shop about it. The ones around here usually have a few sets sitting around for sale.
     
  9. ftn96

    ftn96 1/2 ton status

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    Ok dude, here is the deal. I just got through with this problem back in Febuary. You are correct, your seals may very well be worn. Like wise I tore into my 90 model only to find that the truck had been ran for long periods of time at low RPM's which causes the oil that is in and on any surface inside the valve cover that is not directly in the main pool of oil, to BAKE. It then drys up and crumbles down, getting back into the oil flow. Well, then all the oil goes back to the drain back journals (returns, whatever you want to call them) There is one at each end of each head. So......

    What I did was drain all the oil, then I got a shop vac, flat head screw driver, putty knife, wire brush, or anything that will help you get all that crud outta there.
    Then take a wire coat hanger and run it down in the journals (holes, whatever). Then if you have it, take an air nossle and blow all the loose misc. crap outta there.
    You can go ahead and replace the valve seals while your in there. However, in my case we were short on time and decided to see how it worked with the clean returns. To this day, I'm not smoking at start up nor am I the smoke box in the drive-thru like you described. Hell, If I sat at a red light for more than 2-3 minutes, I'd get a huge cloud when I took off.
    You can also, take a new oil filter, pre-filled with oil and install it. Then take 4 quarts of Kerosene and dump in the oil fill hole. Start the engine. Let is run till it gets to normal operating temperature. Then turn it off.
    Drain the nasty kerosene out, change the filter. Re-fill with oil. Then run it again for about 5-10 minutes at operating temp. Then drain it all out again. Re-fill the oil with new filter and whaaa-laaa. One note thought!!!!
    It is highly recommended to drop the oil pan and clean all the crud out so you dont stop up the oil pick-up.
    If you have the rubber gasket like I have then its cake other than the bolts that are behind the oil cooler lines.

    Hope this helps you in your quest. /forums/images/icons/wink.gif /forums/images/icons/cool.gif
     

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