cyclinder head question

Discussion in '1969-1972 K5 Blazer | Truck | Suburban' started by Roostr84, Jun 6, 2001.

  1. Roostr84

    Roostr84 1/2 ton status

    Aug 19, 2000
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    I have a set of 882 cylinder heads. How are these things for performance. I have heard alot of mixed reviews. How much lift are they effective with. The motor they are going on has a solid cam with .510 lift, not sure of the duration, pretty lopey though. Would a set of vortecs with the appropriate changes to accomodate the lift be a better choice?
    Thanks guys.

    Chris =)
  2. 2quicK5

    2quicK5 Registered Member

    Apr 18, 2001
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    333882 heads are not good for performance usage for several reasons. First they are thin wall castings and will run hot and crack around the exhaust seats. Secondly they have terribly restricted intake ports that will limit the effective rpm of your cam. The intake ports will stall out at around .420 to .450 lift (port flow stops increasing) so the .510 lift won't do much good with these heads. You will need aftermarket valvesprings (dual) for the cam that you are running. They have 76cc chambers and will give you between 8.5 and 9.0:1 compression ratio with flat top pistons.

    Vortec heads are a much better choice as the intake and exhaust ports flow much better. With the cam you are using you will probably see a gain of 30-50 fwhp using the vortec heads over the 882s. The Vortecs will need aftermarket springs matched to your cam also as the stock ones won't cut the lift or the rpm potential of your cam. These heads have 64 cc chambers that will give you 10.0 to 10.5:1 compression ratio with flat top pistons. You will need the extra compression with this cam because of the large overlap it probably has. The vortec heads will require an Edelbrock or GM performance parts intake manifold with the correct vortec bolt pattern. Earlier SBC intakes will not fit. It will also require the '87 and up valvecovers with the center hold down bolts.

    Check with Jim Pace Pontiac,, they sell a pair of vortec heads complete for around $450. They have ones drilled and tapped for pre '86 intakes for $510.


    1972 K5 Blazer: 400 ci, 4 sp, 4" springs, 35" Tires

    2000 Trans Am, A4
    11.97@114 mph

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