What size bolts are these?

[m3talc0re]

I think they are the bolts that hold the carb to the intake manifold. I think the guy that worked on it before used whatever bolts he had and only has 2 or 3.. Anyone know the size these are supposed to be? Thread pattern and length?

Edit: carburetor mounting studs, is that what I'm looking for? I'll have to wait until this afternoon to take it off and actually look XD

Edit 2: This is an 83 GMC Sierra Classic with a 350. Edelbrock 1406 carb

[Bunkerbuilder]

You neglect to state if the carb is the factory quadrojet 4 barrel or an aftermarket carb and also what engine the carb is on.

So edit your post to reflect the information that is missing so the membership can intelligently address the question without being as vague as the  question is.

[m3talc0re]

I didn't even realize I left all that out -_-
Is that what they're called though?

[hatzie]

A stock 4 Barrel Rochester Quadrajet is a Spread-bore carburetor. 
The Edelbrock 1406 is a Square-bore carburetor so it's definitely not a stock manifold.  At a guess it's probably an Edelbrock manifold.
The parts you're looking for are called Carburetor Stud Kits.  They're 5/16" with two different thread pitches and can be purchased short to very long.  The coarse end threads into the intake with fine threads that usually have a tapered end on top to make starting the nuts easier. Since you don't have a manifold spacer these short ones will probably do the job. https://www.amazon.com/Edelbrock-8008-Carburetor-Stud-Kit/dp/B000CN7134

If the rear studs need to be longer you can purchase them up to between 3" & 4" in length.

Get some assorted vacuum caps and replace the black duct tape the previous owner installed to cover the unused taps.
 

[m3talc0re]

I forgot about that tape on there. Hopefully I'll have time this afternoon to take the carburetor off and actually have a look

[Irish_Alley]

A stock 4 Barrel Rochester Quadrajet is a Spread-bore carburetor. 
The Edelbrock 1406 is a Square-bore carburetor so it's definitely not a stock manifold.  At a guess it's probably an Edelbrock manifold.
The parts you're looking for are called Carburetor Stud Kits.  They're 5/16" with two different thread pitches and can be purchased short to very long.  The coarse end threads into the intake with fine threads that usually have a tapered end on top to make starting the nuts easier. Since you don't have a manifold spacer these short ones will probably do the job. https://www.amazon.com/Edelbrock-8008-Carburetor-Stud-Kit/dp/B000CN7134

If the rear studs need to be longer you can purchase them up to between 3" & 4" in length.

Get some assorted vacuum caps and replace the black duct tape the previous owner installed to cover the unused taps.
 

could it be a stock intake with a carb adapter?

[m3talc0re]

That's what it looks like. Carb looks dirty as all heck and the adapter looks like it restricts airflow...  It's a Mr Gasket cat.no.1932. And there's a dang bolt sheared off in one of the front mount holes...

[hatzie]

I stand corrected.  That's a Spread-bore manifold.
The vacuum leak from that broken stud will not help performance.  Neither will the adapter.

I'm not a fan of cheaper Edelbrock and Holley replacement carbs.  They always seem to cost more in time and additional parts than the stock Rochester Quadrajets and they dont seem to work well without constant fiddling.  Quality reman Quadrajets can be had for around $250-$350 that just plain work for years with no drama.  Unless you're looking to wring the last 4hp out of your engine they are good performers and very reliable.  A better intake and exhaust will give you easier hp than a performance carb.

Sent from my SM-P605V using Tapatalk

[m3talc0re]

I do have the stock carburetor.. When I bought the truck, he told me that it sat up for a while and had bad gas in it. I guess he took the carb off and had an edelbrock off another truck he had there to get this one running. Would I be better off trying to rebuild the Quadrajet?

[Irish_Alley]

x2 on what hatzie said. right now you need to get the right intake then if parts are just thrown together like that (probably from the local parts store) they probably just grabbed a bigger carb and went with it thinking it will be more power. i would go with a quad also and get the timing set then hook the timing advance to manifold vacuum not ported like you have now.

for the time being i would try and get that bolt out put it all back together without any vacuum leaks in the base gasket like you probably have now. and set base timing around 16° then hook the vacuum advance to manifold vacuum that way its always there after it starts up.

http://forum.73-87chevytrucks.com/smforum/index.php?topic=32085.0

http://forum.73-87chevytrucks.com/smforum/index.php?topic=31377.0

[m3talc0re]

Slow down Irish, you lost me at hello, lol.

Should I rebuild the Quadrajet or the Edelbrock? All over Google is mixed opinions about which is better.. I do know I can get the edelbrock rebuild kit down the road from O'Reilly's, but I don't think they have one for the Quadrajet. Would it benefit me to grind down the excess aluminum on the inside of that adapter to actually match up to the manifold's passages? Right now, it coveres up a good amount of it.

Edit: I found the numbers on the Quadrajet carburetor and it looks like it came from a buick or pontiac? It's a Quadrajet 17056264. Is that good or bad? I need to find where on that motor it says exactly what it is. The vin on the truck says it came with a 305, but it (supposedly) has a 350 in it. It's unknown where the motor come from atm.

[hatzie]

I agree with Irish.  Take it one step at a time.  That way you don't bite off more than you can chew.

Remove that snapped off stud and clean up the shavings.
Don't change the adapter
Re-install the Edelbrock 1406 with vacuum caps rather than duct tape, use the correct mounting studs, and use new gaskets on both sides of that adapter.
Set the timing to @ 16° with the vacuum advance hose disconnected and plugged.
Plug the vacuum advance into a manifold vacuum port on the carb...  Below the throttle plates or on an intake runner.
See how she runs.  Maybe the PO calibrated it close enough to make it run OK...  Considering the broken stud I doubt it but hope springs eternal.

If it runs close to OK then you can start changing things.  Otherwise do some more testing and poking around.  Troubleshooting is not going to cost you $.

I'd get the Quadrajet re-worked if it's a regular M4ME or M4MC.  I wouldn't mess with a Computer Command Control M4MED Quadrajet.  Too many unknowns.  The electronics in the pickup, to make it work correctly, are unlikely to be unmolested and they may not be working properly even if they are unmolested.

What's the Quadrajet part number?  If you have a stock 1983 Quadrajet from a GM pickup the part number will probably be 1708xxxx or 17xxxxxx.  The last four or six digits will tell you exactly what carburetor you have. 

My comment in my last post stands.  I would install a working Rochester Quadrajet rather than mess with the Edelbrock or a Holley.

I pass on rebuilding some of the more complicated Two and Four barrel Carburetors myself.  The Rochester Quadrajet and the Edelbrock 1400 are not beginner units.  The parts count is way too high.  A Rochester 2G or 1G and my ATV and small engine carbs are easy.  Not those.
What I get for my $ with decent quality re-manufactured carbs is... operations like re-bushing the throttle plate pivot shafts that Joe Six-pack doesn't usually have the tooling or experience to handle (I don't have the patience to do it), the industrial outfits have access to nasty toxic chemicals like Methylene Chloride that actually melts varnished fuel & crud so all of the little passages are cleared out, the carburetor is completely setup & calibrated by someone that knows exactly what they are doing so I can bolt it on and go, and I get a warranty.

[m3talc0re]

Where can I send mine to be rebuilt? The Quadrajet I mean.

The Quadrajet I have is 17056264. Just a quick Google says it cane from like a Buick or Pontiac I think?

From what I've seen on YouTube, the 1406 doesn't look too bad. I may rebuild it myself to get my truck going  until I can get better. And yeah, the sheared bolt is coming out XD

Oh,  I don't remember if I mentioned it or not, but the edelbrock carb has gas leaking out of the side near where the fuel line connects. It's why I took it off. Should I rebuild it or just replace the gaskets?

[philo_beddoe]

x2 on what hatzie said. right now you need to get the right intake then if parts are just thrown together like that (probably from the local parts store) they probably just grabbed a bigger carb and went with it thinking it will be more power. i would go with a quad also and get the timing set then hook the timing advance to manifold vacuum not ported like you have now.

for the time being i would try and get that bolt out put it all back together without any vacuum leaks in the base gasket like you probably have now. and set base timing around 16° then hook the vacuum advance to manifold vacuum that way its always there after it starts up.

http://forum.73-87chevytrucks.com/smforum/index.php?topic=32085.0

http://forum.73-87chevytrucks.com/smforum/index.php?topic=31377.0

Hey i remember that famous rich weyand thread. I went through all that back when i was a rookie. Wait, i still am. Good teaching there.

A full rebuild on that qjet or get one here. I paid $195, great service, when i got mine it looked brand new. No problems since.

http://www.nationalcarburetors.com/

[m3talc0re]

I'll have to check them out. I bought the rebuild kit for the edelbrock, so I'll be working on that today.