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I need a 350

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by johnny, Aug 30, 2001.

  1. johnny

    johnny Registered Member

    Jun 29, 2001
    Likes Received:
    I want to replace the 305 in my 86 k5. I understand that that year they changed to a 1 piece rear main seal. Do I really NEED to buy a replacement with the one piece? Also will my emisions be ok with the new motor as long as all the stock smog stuff is still on?

    My paycheck = more K5 parts
  2. loudnowlouder

    loudnowlouder 1/2 ton status

    Jan 29, 2001
    Likes Received:
    Ellicott City, MD
    you really dont need to replace it with a 350 that has a one piece rear main seal....but it makes sense to buy one with it...i have an 85 and i swapped out the 305 to a new 350...the only real difference is that the flywheel bolt pattern is changed...so you'll have to get a new flywheel...other that that there really arent any differences you need to worry about.

    i'd personally stick with the one piece design...i had a defective rear seal when i put the new enigne in...it was a snap to change...the older models you have to drop the crank to change the rear main which means a hell of a lot of more work and pain...i was able to change mine in an afternoon by dropping the tranny...the older ones you'll have to pull the engine.

    as far as emissions...they should be better than before if the 350 is new or rebuilt...keep the stock smog crap and stock exhaust and you really shouldnt have any problem.

    so if you already have an older 350 or you're getting a good deal on one that doesnt have the one piece..go for it..

    good luck
    adam H

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