Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Maiden Voyage!!! and a question....

Discussion in '1969-1972 K5 Blazer | Truck | Suburban' started by Max, May 17, 2001.

  1. Max

    Max 1/2 ton status

    Joined:
    Feb 19, 2000
    Posts:
    158
    Likes Received:
    0
    Location:
    Durham, NC
    Hey all,
    I had my maiden voyage on the 71 Jimmy (most likely to be named
    Tigger due to the orange color with probably black stripes being
    added if body work is done). Got a set of 35s from Costco. They
    have BFG Muds at really good prices, including mount, lifetime rotate
    and balance, road hazard (hehe). The 35's were 158 including all
    that. $148 for just the tire not mounted, etc. Anyhow, i digress,
    got the tires and took a ride. Was fun to finally get to roll down
    the road. Now...I am starting to find other issues cropping up and
    wondered if anyone could help me track them down.

    The main problem seems to be it doesnt really want to go too fast.
    The engine runs great out of gear, but in gear, I think I can feel
    the tranny shift twice (th350 3 spd), but at the top gear, it doesnt
    really have much pick up or want to go too fast. Got the speedo up
    to 40, but thats about it. Engine is '87 350 with a quadrajet. Any
    suggestions?? What to check?? Ideas???


    PS: 4 wheel drive works as i put it up on a big rock in my yard that
    the jeep couldn't get up on :) Pictures soon.

    Thanks in advance,
    Alan
     
  2. Triaged

    Triaged 1/2 ton status

    Joined:
    Feb 21, 2001
    Posts:
    3,808
    Likes Received:
    0
    Location:
    CA (LA/OC area)
    It may be running lean due to a cloged fuel filter.

    '71 Blazer CST with alot of rust
     
  3. Chris Demartini

    Chris Demartini 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    2,406
    Likes Received:
    1
    Location:
    Dumont NJ 07628
    <font color=blue>If you still have the stock axle gears, you need to change to 4.10s or 4.56s to get some speed back and keep the trans from hunting for gears.</font color=blue>

    [​IMG]
     
  4. Steve_Chin

    Steve_Chin 1/2 ton status

    Joined:
    Mar 6, 2001
    Posts:
    1,126
    Likes Received:
    0
    Location:
    Foster City, CA, USA
    I agree with Biggray71. Gears are needed because the truck originally came with 30" or 31" tires. Bare minimum, I'd change to 3.73:1 gears, with 4.10:1 being preferrable.
     
  5. Max

    Max 1/2 ton status

    Joined:
    Feb 19, 2000
    Posts:
    158
    Likes Received:
    0
    Location:
    Durham, NC
    It has 3.73s in it.
     
  6. HarryL

    HarryL 1/2 ton status

    Joined:
    Feb 25, 2001
    Posts:
    139
    Likes Received:
    0
    Location:
    Layton, UT (20 miles north of SLC)
    Max,

    According to my trusty engineering calculator, going from a stock 28" tire and 3.73's to 35 BFG's now gives you a gear ratio of 3.0 (actually 2.984, but that's close enough).

    You shouldn't be having probs with top speed just because of bigger tires. As the other fellow stated, check your fuel filter.

    Is the engine timed correctly? Was the parking brake on? :-)
    I say that in jest, but something doesn't sound right. Were you in 4wd High? Low?

    just thoughts

    Harry with 35" BFGs and loving it
     
  7. Leinie

    Leinie Registered Member

    Joined:
    Mar 5, 2001
    Posts:
    38
    Likes Received:
    0
    Location:
    Shakopee MN
    First, I would double check your gear ratio, then I would check your engine numbers. I've heard of people getting 305's that were supposed to be 350's.
    A 305 with 3.07 gears with your tires would be a real dog!
    I hope that is not the case, but check it all out.

    72 K5 CST X 2
     
  8. 71RestoRod

    71RestoRod 1/2 ton status

    Joined:
    Mar 7, 2001
    Posts:
    178
    Likes Received:
    1
    Location:
    Evergreen, CO
    No power or no speed? Are you sure that you’re grabbing all the gears? You might have a bad vacuum modulator on your TH350, or perhaps a vacuum leak keeping you from shifting into third. In second, it seems like you would be topping out around 40 mph.
     
  9. chevyfumes

    chevyfumes Court jester

    Joined:
    Feb 24, 2000
    Posts:
    38,584
    Likes Received:
    266
    Location:
    Watch for the muzzleflash!
    had the same prob with mine when I first got it, stupid modulators. There is a screw inside the end you can turn that should fix the problem, or just buy one for 20$, just make sure thats the problem first though...

    [​IMG]<font color=blue> I'd rather have a bottle in front of me, than a frontal lobotomy!
     

Share This Page