poor gas mi

[richard]

1981 c 10 short box fresh 350 motor quadra jet carb 308 rear end turbo 350 trans it sounds like it could use another gear any one have the same set up pulls like its got 456 gears

 

[rpcraft]

What size is your driven tire? 3.08 isn't really a short gear. Usually with a 31 inch tall tire it will be looking for something more like a 3.73 to be running happy so you must be running a really small tire to be complaining about engine speed with a 3.08 and a 3 speed auto.

 

[rpcraft]

One other thought, might be your fan clutch needs to be replaced. Those things make a huge amount of noise when they fail and lock up while driving closer to highway speeds.

 

[idahovette]

One other thought, might be your fan clutch needs to be replaced. Those things make a huge amount of noise when they fail and lock up while driving closer to highway speeds.

This happened to me on a vacation in Montana. Thought my trans quit shifting into 3rd, finally quit listening and counted shifts. Got out popped the hood and grabbed the fan and found out the clutch was froze tight. It did make a heck of a lot of noise pulling all that air. Drove home without losing the H2O pump, but slower than normal. All this with a 9 1/2 foot self-contained camper 2 kids and a wife worrying if we were gonna get home. FUN TIMES!!!

 

[rpcraft]

That happened on my 77 and I do recall it was noisy as hell. I finally replaced it with a flex fan because at the time that was the rage but apparently that is still a bit of a power robber at speed as well.

 

[idahovette]

yeah kinda scary to start with till you find out what's going on and 250 miles from home hoping that your old K-20 will make it.

 

[rpcraft]

I remember a symptom mine also had was when sitting idling the temp would creep up and eventually I could smell the coolant coming out of the radiator and back then I was not saavy enough to know to put a catch can on it.

 

[idahovette]

We all live and LEARN (hopefully)