SLS engine and trannie in a STS?

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Northstar Engines and System Technical Discussion Discussion, SLS engine and trannie in a STS? in Cadillac Engine Technical Discussion; I have a 99 SLS and am wondering if I can put it into a 99 STS? Does anyone know ...
  1. #1
    jtlahr is offline Cadillac Owners Member
    Automobile(s): 2001 Seville, 1999 SLS
    Join Date
    Oct 2009

    SLS engine and trannie in a STS?

    I have a 99 SLS and am wondering if I can put it into a 99 STS? Does anyone know or has anyone done this?


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  3. #2
    kjhansen's Avatar
    kjhansen is offline Cadillac Owners Fanatic
    Automobile(s): 1995 Cadillac SLS
    Join Date
    Oct 2007
    SW Missouri

    Re: SLS engine and trannie in a STS?

    Should be a bolt-in although I've never done it. From what I've read, they're the same engine and transmission--the main difference is the camshafts, which is not a player for the installation--although you might want to use the SLS computer too. Also, the radiator I got for my SLS was an STS radiator and it has oil cooling line attachments on the passenger side, and my SLS has a separate oil cooler hanging in front of the radiator and A/C condenser. So there might be some minor adjustments you'll have to make. Take into consideration that my SLS is a '95 and your cars are both 99's so a lot might have changed...

  4. #3
    Ranger's Avatar
    Ranger is online now Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Woodstock Ill.

    Re: SLS engine and trannie in a STS?

    You'll have to swap the PCM with it.

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