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Is it alright to run at 3000-3400rpms

Discussion in '1982-Present GM Diesel' started by protechk5, Mar 17, 2007.

  1. protechk5

    protechk5 1/2 ton status

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    I got a 6.2/sm465 (no overdrive) with 4.56's on 33's. Is it alright for me to be doing highway speeds like 60-65mph which is around 3200rpms. I read somewhere where the stock rev limiter is set way low, and that it can run at 3000-3500rpms all day long. I try to stay around 60mph but it sounds like it is screaming.
     
  2. ccatlett1984

    ccatlett1984 1/2 ton status

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    the 6.2's can run against the governor all day long.
     
  3. protechk5

    protechk5 1/2 ton status

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    alright good thats what I was hoping
     
  4. imiceman44

    imiceman44 1 ton status

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    Yeah my buddy with a crew cab 2wd with 4.56 and 28" tires used to run it at the limit for hours, did that for 3 years then got tired of the noise and the low mileage so switched to 3.73
    :D
     
  5. muddybuddy

    muddybuddy 3/4 ton status

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    once u get the 37s/40s itll be fine. you better not switch to 4.10s
     
  6. Ronnie4wd

    Ronnie4wd 1/2 ton status GMOTM Winner

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    x2.
     
  7. kennyw

    kennyw N9PHW Premium Member

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    As long as your block isn't cracked around the main bearing saddles you will be ok... My crank snapped at ~70mph going down the freeway running up to the gov limit. Found the block was missing chunks and cracked around the same main web as where the crank snapped when I tore into it later.
     
  8. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    It may be fine to run it at those rpm's...but trust me when I say it's very hard to listen to for long. On the drive down to Moab my K5 was spinning at 2600-2800 rpm (21 hours each way... :doah: ) and it was very loud...loud enough to wear you out and so loud the stereo was nearly inaudible except at full volume (which also gets old quick)

    Rene
     
  9. protechk5

    protechk5 1/2 ton status

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    yeah i know. i was thinking maybe it could permanently damage my hearing? mine is even louder b/c i cut out the tranny hump and havent sealed it up all the way, also the holes in my firewall from the clutch rod. oh well i should have either 37's or 40's soon, maybe even with4.10s if i go with 37s
     
  10. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    Well, mine has no carpet, plenty of holes in the firewall (clutch rod and various old wiring holes :doah: ) It also has no insulation underhood or on the firewall...and it's on 39.5" TSL's. My triple stick shifters have masking tape as a 'boot'...

    By comparison my '83 C1500 is so quiet you can whisper to each other while cruising on the highway.

    Rene
     
  11. k204dr

    k204dr 1/2 ton status

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    you're gonna need to put some wads of paper towl in your ears at least, if not some earplugs. you will be def in short order!
     

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