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Question about Crate Motors

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Alaskan85K5, Sep 7, 2001.

  1. Alaskan85K5

    Alaskan85K5 Registered Member

    Sep 5, 2001
    Likes Received:
    Anchorage, AK
    Okay I have a question, my 85 has a 5.0L (305) in it. It has well over 100,000 miles on it and probably needs a bit of work. I keep reading about people swaping for crate engines. I'm considering doing the same thing, though I really want to maximize fuel economy. Anyway my question is I alwasy read this

    "should only be used in 1973 and earlier pre-emissions street vehicles or

    any year off road vehicles."

    Does this mean I can put a crate engine in my 85, because I have to use all the emissions stuff? Can I put the 350HO in even though I currently have a 305? Out of the GM crate engines what would be my best bet for good fuel milage, keep in mind I also use this to tow my toys (4-wheelers, snowmobiles, etc...). I use my blazer mostly for a daily driver and want to get the best fuel economy possile.

    Could someone explain this all to me.
    I'm concerned I won't pass IM inspection.


    Remove the NOSPAM from the e-mail address to send me an e-mail.
  2. Mreetz

    Mreetz 1/2 ton status

    Jun 26, 2001
    Likes Received:
    Subs of Denver, Colorado
    As long as you reuse alll your current emission equipment on your current engine, you'll be fine passing.

    1984 K-5
    4" lift
    35x12.5 MTs
    buildin a 400 for it, any info greatly appreciated
  3. Hossbaby50

    Hossbaby50 3/4 ton status

    Sep 1, 2001
    Likes Received:
    Peoria, AZ
    I had a 305 in my 85 Jimmy. I had it swapped out to a GM crate 350. I had the stock crate motor for awhile, but two oil rings went out after about 15K. The crate motors come with a 3 yr. 36K warranty so I got a new one free. I had them put in the 300 hp crate 350 for an extra $500. It was totally worth it. The GM motor I bought with 300hp has been replaced with the 330hp crate motor. I would go for that one if your going to haul anything. You will need all the emisions stuff on it , but the motor should pass easily. Mine passed fine in Phoenix AZ which has extremely tough emission laws. I get about 9 -10 MPG intown and 12-13 on the highway. When I had the 305 replaced with the 350 I actually got better MPG with the 350. Most of the 305 parts will swap onto the 350, except a few parts you'll have to buy. There was a recent post that told what new parts you would need. Hope this helps you. Oh ya, the 300hp motor I have now is holding up fine. It has over 30K with no problems.

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