K5 Blazer 1969-1994
While this model ended its run, it is not uncommon to see them on the road or off, years after production end.
Platform: Truck, GMT 400

my 71 K5 is really slow

Thread Tools
 
Search this Thread
 
Old Mar 28, 2019 | 6:34 PM
  #1  
K5Dave's Avatar
Thread Starter
CF Beginner
 
Joined: Mar 2019
Posts: 2
Likes: 0
Default my 71 K5 is really slow

Hey Everyone .. I'm new here

I bought a 71 K5 CST 4x4 about 6 months ago.. It runs great, has the stock engine, its lifted a bit with 35's
I take it on the freeway and going up even a slight grade, I barely get to 55mph .. and top speed on flat is about 65 ..

I don't need to go super fast, but is the gearing off or? The guy before me used it pretty much for cruising the desert

Thanks for any help or suggestions --

Reply
Old Mar 28, 2019 | 8:13 PM
  #2  
oilcanhenry's Avatar
CF Monarch
 
Joined: Oct 2017
Posts: 4,605
Likes: 269
From: USA
Default

Whats under the hood? Transmission , axle ratio?
Reply
Old Mar 29, 2019 | 11:56 AM
  #3  
K5Dave's Avatar
Thread Starter
CF Beginner
 
Joined: Mar 2019
Posts: 2
Likes: 0
Default

Originally Posted by oilcanhenry
Whats under the hood? Transmission , axle ratio?
Its got a 350 engine.. ‎3-speed TH-350 automatic;, and I'm not sure how to know what the axle ratio is?
Reply
Old Mar 29, 2019 | 1:03 PM
  #4  
oilcanhenry's Avatar
CF Monarch
 
Joined: Oct 2017
Posts: 4,605
Likes: 269
From: USA
Default

Originally Posted by K5Dave
Its got a 350 engine.. ‎3-speed TH-350 automatic;, and I'm not sure how to know what the axle ratio is?
Probably a 3.42, 3.73 or 4.10. Just jack a wheel up after you marked it and the driveshaft it with something easily visible like liquid paper and turn the driveshaft or wheel. Count the revolutions and you have your axle ratio. If you spin your tire once 360 degrees, and your DS turns a bit over 4 times, you have a 4.10 to one ratio for instance.

Last edited by oilcanhenry; Mar 29, 2019 at 1:05 PM.
Reply
Old Mar 29, 2019 | 3:07 PM
  #5  
Irish_alley's Avatar
I'm here for the party
5 Year Member
Liked
 
Joined: Feb 2019
Posts: 1,467
Likes: 83
From: Maryland
Default

How to determine what ratio you have without removing the cover

also check your timing and for any vacuum leaks
Reply
Old Mar 30, 2019 | 5:08 PM
  #6  
Kazoocruiser's Avatar
CF Active Member
 
Joined: Feb 2018
Posts: 185
Likes: 1
From: Currently the Candian Gander is wintering over in New York.
Default

Might be time for a fuel filter.
Reply




All times are GMT -5. The time now is 5:42 AM.