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6.2, 6.5L Head Questions

Discussion in '1982-Present GM Diesel' started by josephn, Mar 19, 2001.

  1. josephn

    josephn 1/2 ton status

    Nov 3, 2000
    Likes Received:
    Can you run 6.5L heads on a 6.2L?
    Will the 6.2 exhaust manifold bolt up to the 6.5L head?
    Do they really breath better than the 6.2L heads?
    I am replacing my head gaskets so already have my heads off and found a couple for 80 bucks, would it be worth it?


    1982 6.2L Diesel K5 Blazer, TH700, 31 inch tires.

    Fire ALWAYS makes it better.
  2. AgDieseler

    AgDieseler Certified Scrap Producer Premium Member GMOTM Winner

    Jan 25, 2001
    Likes Received:
    (I got this from thedieselpage.com)

    "These heads are interchangeable right for left and vice versa.

    "1982 model 6.2L heads use coarse thread injectors (M24 X 2) and the 1983-on (including the 6.5) use fine thread (M24 X 1.5) injectors.

    "From all the information I have, 6.2 and 6.5 cylinder heads are interchangeable across all year models. This means 6.2 heads will work on a 6.5, and 6.5 heads will work on a 6.2. Installing 6.2 heads on a 6.5 or installing 6.5 heads on a 6.2 will require a set of fuel lines that match the particular heads you're using because of different injector angles. You have to be careful to always install a matched set of heads that have the same casting number. There are substantial differences between model years in pre-combustion chamber design and valve diameters. Generally, the newer heads (and especially the "J" models for the 6.2 and "F" models for the 6.5) will allow your engine to produce more power. However, older "C" series heads will help deliver better fuel economy."

    I rebuilt my 6.2L heads with 6.5L prechambers, and other than the injector angle, I have basically 6.5L heads.

    Hope this helps,

    '85 diesel burban

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