Author Topic: 83 chev K20 military  (Read 1650 times)

Offline 101 airborne

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83 chev K20 military
« on: October 01, 2017, 08:50:17 PM »
My quadrajet  leaks down over night making it hard to start cold ,however after that its ok the rest of the day.It also whistles at 55mph and gets about 8 miles per gallon. I thought it could have a vacuum leak , but I put a vac gauge on it and pulls 12hg at idle. I don't want to rebuild this carb because it might have worn throttle shaft or other internal leaks common quadrajets .What would be a good replacement and would I need adaptors. Any help would be great. Also its a 350 cu with 4.56 gears ,th400 trans  Thank you from Kansas.

Offline 1967KaiserM715

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Re: 83 chev K20 military
« Reply #1 on: October 02, 2017, 11:41:10 AM »
Get a rebuilt quadrajet, best carb for a mostly stock 350. Maybe not yours, but it should still be good as a core.

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Online bd

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Re: 83 chev K20 military
« Reply #2 on: October 02, 2017, 01:36:37 PM »
A stock 350 engine should idle with >16" Hg vacuum.  Spray for vacuum leaks using aerosol carburetor cleaner.  Pay particular attention to the carburetor base gasket area and physically inspect the PCV and vacuum brake booster hoses for sponginess and perforations.  Does the engine have an EGR valve?
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline 101 airborne

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Re: 83 chev K20 military
« Reply #3 on: October 07, 2017, 12:27:02 PM »
I will ck all you suggested before any thing else. Thanks

Offline roundhouse

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83 chev K20 military
« Reply #4 on: October 08, 2017, 11:19:57 PM »
Your truck originally had a diesel ?

The 4.56 years will let you run some 35 or 37 inch tires
We have 35s and 3.73 gears
Wish we had 4/56

Anew carb will help a little but a full size V-8 4 wd truck isn't going to get more than low teens at best

Not even a new one
I drive a 2017 3/4 ton 4wd Silverado at work and it averages 13 mpg
Gets about 6 when I'm towing a bobcat or mini ex
« Last Edit: October 08, 2017, 11:24:25 PM by roundhouse »