tjcustomranger said:

So 2243 at 65
2070 at 60 which is what I'll be driving at

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That is a decent rpm for that engine

tjcustomranger said:

What is the factory speedo cable? # of teeth?

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Not sure

I haven't run through all your math yet...but remember it's proportional. If your speedometer is 8 mph fast at a true 60 mph, it'll be 4 mph fast at a true 30 mph.

its only 2 to 4 off at 20. but haven't tested it past that. i don't know how accurat emy math is yet but sounded right in my head. if thats really the rpm why would my mileage be so ridiculously bad? even with the full time i don't see why its so bad. its like 7 at the most. my gas gauge is accurate once its at 1/8 of a tank haha

You need to go through the engine...timing, cap, rotor, carb....stuff we have all told you...in a methodical fashion....it's the only way to determine what (if anything) is wrong.

tjcustomranger said:

There is a difference of 76 tire rotations between 35 and 30 inch tires per mile which is a difference of 700 feet. When my tach goes a mile I really went 5980 feet. Or 1.13 miles.
So when I do 60 miles an hour with 30s I travel 60 mile in an hour and with 35s I would be traveling 67.8 miles. But the truck still thinks its 60.
So my speedo is off about 8-10 mph. Right?

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I can't really follow your math here...

My back-of-envelope reckoning suggests that a 30" tire has to go around 672 times to equal a mile, while a 35" tire only has to spin 576 times.

Spinning the 35" tire 672 times makes distance of 6172', or 1.17 mi.

Meaning at an indicated 60 mph, you're actually traveling 60*1.17=70 miles in an hour.

In other words, your road speed is 17% faster than your gauge says. Multiply the gauge reading by 1.17 to get road speed.

Of course, the easy way to get to this value would have been 35/30=1.17...all the other values cancel out of the equation.


Then, too, there are a couple big assumptions made in all the above calculations- both of which are wrong. First is that the true rolling diameter of the tire is the nominal size, second is that the speedometer would be correct with the 30" tire. They may or may not be close enough for these purposes...I wouldn't bet on it, but it's all we've got.

Easiest way to figure it out and know you're right is to borrow a GPS unit and drive around with it.

I've gone through all of it. The only things that have changed since I last checked it was the pcv valve.
Would that effect it like that?

I need a 15 tooth get which they don't have so I have to change the drive gear too. So what would I do with the other gear?

Try these guys...

http://www.quad4x4.com/

websites not up currently. i'll try again in a little bit.
the carb is 1 1/2 turns on one screw and about 1 and 5/8's on the other because it had a slight knock on one side. i don't usually punch the gas and don't drive it with a lead foot. i put it in neutral whenever i'm slowing down or i'm not moving. the timing is set at 7. i rebuilt the carb all the plugs are gapped correctly. the wires all replaced, crap and rotor replaced. ignition, "brain" and such replaced. has 3.50s in it. its full time 4wd and is always in 4 hi. the vacuum lines that aren't hooked to anything are plugged. not sure what else to check compression is 115-126. the choke is open, new air filter, no more of that hot air duct i snapped it off of the manifold, fuel filter and line was replaced. what else would i check??

Have you put a vacuum gauge on it?..and was the carb rebuild complete...like soaking and cleaning in xylene/acetone and all gaskets etc replaced?

yes. i bought a gallon of cleaner and soaked the carb in a bucket along with everything in the carb except plastic stuff. and then i rebuilt it with a kit from oreily's and bought a can of carb cleaner and a box of qtips. cleaned it all made sure i put everything together correctly and didn't leave anything out. stuck it on the truck and adjusted it. then put new base gaskets on.

i haven't done vacuum gauge yet i think my dad has one i can borrow, which ones do i check?

after i rebuilt it the mileage did go up a little bit, it also doesn't help that i burn up a 1/4 gallon starting it without a choke.

both axles are leaky, the rear is so full of mud and oil it stopped leaking but the front is leaking out. what oil should i put back in them once i change out the gaskets? and what all should i look for while its apart

Truck sounds like a tea kettle I think it's the carb I went trough the vacuum lines already. What could it be

tjcustomranger said:

yes. i bought a gallon of cleaner and soaked the carb in a bucket along with everything in the carb except plastic stuff. and then i rebuilt it with a kit from oreily's and bought a can of carb cleaner and a box of qtips. cleaned it all made sure i put everything together correctly and didn't leave anything out. stuck it on the truck and adjusted it. then put new base gaskets on.

i haven't done vacuum gauge yet i think my dad has one i can borrow, which ones do i check?

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At the bottom of the carb...you want to see how stable the vacuum is.

Truck is parked for most of the winter. I'm buying another vehicle this February or march and then will begin to find a place to store the truck until I get a new house or something where I can tear it down to the frame and restore it. I'm going to make a 390, rebuilt the tranny with a shift kit, swap to a 205 with an overdrive redo all bearings and seals in the axles.
Fix clean up the frame and have it either powder coated or rhino lined. Build an exhaust
My headache rack and rock sliders
Maybe a new to me bed as well as front clip.
Going to build tube doors for te summer
Maybe fix the ac
Need to redo the interior and replace the windshield
Cowl hood maybe
Cab lights
Cargo lamp
Stereo and speakers
New rear bumper
New rear gas tank and selector

not quite done yet

First i got bored so i made a spacer out of a 308 shell...
thought maybe i'll go farther and start doing stuff like that in the interior and so found the shift knob off my 74 ripped the end of and put a 30-30 on it.

Thats original.

is that a good thing or bad thing?

locks. couldn't find my old piston a buddy might have one though