Much appreciated. Yeah since one of the studs is snapped, and the other one had a bolt cross threaded, I just picked up a couple replacements to put on. The 3/8s debacle makes me nervous since 5/16 is the universal size, but a 5/16 nut didn't fit, so logically it must have been drilled out at some point. Still amazed the nut came off, because it got stuck on the old one after I took it off.

 

I wonder if the the PO kept having the carb come loose and did what he had to to keep it tight?
Them straight six carbs have been known to loosen up and cause run issues.
Dave ----

 

Well, this is just a maybe, based on what I do know. Vacuum leaks will lean out an otherwise correct set up, so if you adjust carburetor mixture screws with vacuum leaks, your setting is going to be over rich if those vacuum leaks are then fixed.

So then say you again adjust the mixture screws to get back to correct, you are setting towards lean now which means using less fuel now since you cut off air from vacuum leaks ..., and if a leaky inlet needle and seat was letting a little extra fuel in, the extra was being absorbed by the rich setting when you had vacuum leaks ... but since you have now fixed those leaks and readjusted the mixture screws, you aren't using the fuel coming in past a worn inlet needle and seat, but the fuel is going to come in, so you find leaks now caused by excess fuel slipping past the inlet needle and seat, fuel that was being used poorly when you had those vacuum leaks.

I'd rebuild the carburetor, including new inlet needle and seat which is often referred to as float needle and seat. I'd also attempt to find a new float, yours may be heavy if it's solid and has absorbed fuel ... or if brass and it has a leak in its float. If brass, shake it good and listen close for any liquid inside it.

As a side note, when I was very young, I was taught to coat both sides of my carburetor base gaskets with a thin coat of plain old axle grease. It works in my experience.

 

Tbear, being he is selling the truck and has a new carb I would go with new and tune it and get the next owner the old carb, unless I could use it on something else, and tell them it needs to be rebuilt and dont look back when they drive off into the sun set LOL
Dave ----

 

Thats what I am hoping. I have my fingers crossed that they match and the PO didn't just drill one of them out and left the half broken one in. Wouldn't be the end of the world if one was 5/16 and the other was 3/8, just makes for another run to the hardware store.

 

Well had a hiccup with the "reman" carb. Tuesday I had it all installed and running, truck sounded way crisper and my fuel smell was all gone. Didn't have a vacuum gauge so ear tuned it as best I could and shut it off. Got my vacuum gauge yesterday, went out to warm her up for a few minutes so I could change the oil and get her all dialed in, and had a carb problem. Didn't want to fire, and about 5 seconds of trying to start it, threw fuel all over my windshield and leaked out of the throttle shaft. So, has a stuck float. Took her off, and will be picking up a replacement after work seeing as I don't want to tear into a new carb. My next question is, warmed up and at idle should the vacuum be somewhere between 18-20? And whats a good idle rpm? I dont have a tach installed but my neighbor has a tach gauge we can hook up to set it. Good news is I got the broken stud out, and they were both 3/8 studs as a replacement so no problems there.

 

Thanks for the input! I thought it would be good knowledge for me to attempt a rebuild, but someone above responded that if it is leaking out of the throttle shaft, a simple rebuild won't address that problem. When I took my old one off, I was able to shift the shaft a little bit.

 

Yea that was me, if the shaft can be moved around the shaft & carb body are warn and will cause a vacuum leak.
If you want to see what makes it tick by all means keep it and pull it apart and see.

On the vacuum I would say that good readings for a stock motor in good shape.
Thing is it cant be bouncing around as that shows a problem.

On the RPM is the truck a stick or auto, no sticker on the radiator support or firewall?
Got no book on the truck even one of the cheap ones from the parts store as it would have that information.
Stick I would set it to 600+/- RPM, auto 800+/- in gear both up to temp and adjust from there.
Timing you can set to 10* BTDC sticker might of said 6* BTDC and it ok if you have smog check.

Dave ----

 

Oh okay, I should have gone back to see who originally said that. Got the new carb on last night, I will dial it in after work. It is a manual, but no I couldn't locate a sticker on the radiator/firewall. No smog check and I want to say I have my timing set at 10* already. I might need to adjust the cold idle because it seems very high. A while back when I was getting a gasoline smell in my oil I assumed it was the fuel pump leaking, but I swapped that out so it was definitely the carb. Hopefully it all goes smooth later today and I can get back to cruising it before it sells. Didn't imagine it would take this long to sell a rust free truck but I can't control that!