Does this look right? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Andy4639 · 10-26-2019, 07:55 PM

Took the carburetor off tonight and found it only had 2 bolts holding it down and both of them where loose. I thought dang 2 of them where either gone are broke off but not either one. The gasket only had 2 of the 4 bolt holes cut. It's been like this since I bought it cause I haven't touched it. Even when I had the carburetor rebuilt they said nothing about it.
The trucks been backfiring bad lately I guess I know why now.

I put it back together with all 4 bolts and lock washers. I also found the passenger side exhaust flange loose again!

firedemon · 10-26-2019, 08:04 PM

I used to see holley 2 barrel carbs on mopar like that back in the day

**AussieinNC** · 10-26-2019, 08:05 PM

2GC carbs sometimes only have two studs and nuts retaining them...
probably a cost saving exercise....

Check out that wire laying along the intake under the accelerator rod...looks like its got bare sections that could ground out...

Backfiring could be lots of things...

Air leaks, bad accelerator pump, bad timing, bad timing chain...

Start with basics,,,,check carb for lack of accelerator pump squirt, check timing, check for vacuum leaks...

Andy4639 · 10-26-2019, 08:11 PM

Quote:

Originally Posted by AussieinNC

2GC carbs sometimes only have two studs and nuts retaining them...
probably a cost saving exercise....

Check out that wire laying along the intake under the accelerator rod...looks like its got bare sections that could ground out...

Backfiring could be lots of things...

Air leaks, bad accelerator pump, bad timing, bad timing chain...

Start with basics,,,,check carb for lack of accelerator pump squirt, check timing, check for vacuum leaks...

Yep I missed that. I look at it tomorrow. Thanks!

**Steeveedee** · 10-26-2019, 10:31 PM

Quote:

Originally Posted by AussieinNC

2GC carbs sometimes only have two studs and nuts retaining them...
probably a cost saving exercise....

Check out that wire laying along the intake under the accelerator rod...looks like its got bare sections that could ground out...

Backfiring could be lots of things...

Air leaks, bad accelerator pump, bad timing, bad timing chain...

Start with basics,,,,check carb for lack of accelerator pump squirt, check timing, check for vacuum leaks...

I've never seen a 2GC with only two fasteners holding it on. What year(s) did the general use that mounting style, any idea?

Andy4639 · 10-26-2019, 10:40 PM

The intake is on a 350 but it's not the original motor for the truck. I'm going to a 4 barrel Elderbrock over the winter. But for now it will do.

**special-K** · 10-27-2019, 07:44 AM

When does it backfire?

68 P.O.S. · 10-27-2019, 08:02 AM

Quote:

Originally Posted by special-K

When does it backfire?

...and to be clear, is it backfiring through the carb?

Andy4639 · 10-27-2019, 08:04 AM

Quote:

Originally Posted by special-K

When does it backfire?

Just when you let off the gas. I haven't drove it yet. I hope between the manifold ring being loose and this I have fixed it. I hope to drive it today and see.

68 P.O.S. · 10-27-2019, 08:09 AM

I hope it's that simple as well. If so, double check the timing. It may have been adjusted to run with the carb the way it was

Andy4639 · 10-27-2019, 08:30 AM

Quote:

Originally Posted by 68 P.O.S.

I hope it's that simple as well. If so, double check the timing. It may have been adjusted to run with the carb the way it was

True that! Yes I will check it today. I have been putting some stuff off on it because of my daughter 68 build. But I need to address these.
I hope it's OK though now.

**AussieinNC** · 10-27-2019, 09:27 AM

Quote:

Originally Posted by Steeveedee

I've never seen a 2GC with only two fasteners holding it on. What year(s) did the general use that mounting style, any idea?

I have found two bolt carb mountings on 70's on engines, mainly 305's....

Has the OP determined the engine is a 350 ?

As the OP mentions the engine is not original...it may just have the small port 2 barrel manifold bolted on...

Andy4639 · 10-27-2019, 10:12 AM

Quote:

Originally Posted by AussieinNC

I have found two bolt carb mountings on 70's on engines, mainly 305's....

Has the OP determined the engine is a 350 ?

As the OP mentions the engine is not original...it may just have the small port 2 barrel manifold bolted on...

According to the guy that I bought the truck from it is a Corvette 350 out of like a 70's model.
Here are a few pictures of it.

Barnfind46 · 10-27-2019, 12:53 PM

So it got upgraded to the super rare Corvette option!

Andy4639 · 10-27-2019, 01:13 PM

Quote:

Originally Posted by Barnfind46

So it got upgraded to the super rare Corvette option!

Correct!

firedemon · 10-27-2019, 02:26 PM

i have often wondered what all those old corvette are running for motors now that they have all been pulled and put in everything else

3767 · 10-27-2019, 04:16 PM

As mentioned by a previous post, timing or even a broke exhaust rocker arm/valve spring. Reason.....u said it backfired when u let off of it. If truck started ok and idled ok would have 2 b a small vacuum leak. A big 1 would show by a bad idle. Due to back fire being when u let up, loose manifold or something n the rocker arm exhaust valve. If u are gonna swap it for a 4 barrel, u may want to pull those valve covers and have a look at all of them . good luck andy.

rsavage · 10-27-2019, 05:23 PM

I had one on the 305 I took out of my Blazer when I began stripping it out. Late 70's or 80's. Mine had an egr valve on the intake. Does yours Andy?

**AussieinNC** · 10-27-2019, 06:54 PM

Ahhh! The old Corvette 350 situation.....

1/ Corvettes with V8 engines never came with a 2 bbl carb
2/ The intake manifold looks like a 307 manifold....small port runners
3/ If you can, find the engine number, passenger side front of block on a pad level with where block meets head
4/ If you can, post a pic of the front face of the drivers side head showing the casting blocks
5/ Drivers side back of engine is a cast in number...post the number and we can identify the engine for you

Andy4639 · 10-27-2019, 09:00 PM

Quote:

Originally Posted by rsavage

I had one on the 305 I took out of my Blazer when I began stripping it out. Late 70's or 80's. Mine had an egr valve on the intake. Does yours Andy?

No EGR valve on mine. I got her running as good as she ever has ran guy's. The vacuum hose off the PVC valve where it goes into the motor was maybe 2 threads deep. There where no clamps on either end but there is now. It took me a while because I kept thinking it was the carburetor leaking.
Got almost 15 lbs of vacuum on my gauge at idle setting the mixture screws. I set the RPM's a little high but think I can lower them just a bit more with the throttle screw.

toolboxchev · 10-28-2019, 06:28 PM

Now I can tell, that IS a Vette Motor!

toolboxchev · 10-28-2019, 06:39 PM

Quote:

Originally Posted by Andy4639

Took the carburetor off tonight and found it only had 2 bolts holding it down and both of them where loose. I thought dang 2 of them where either gone are broke off but not either one. The gasket only had 2 of the 4 bolt holes cut. It's been like this since I bought it cause I haven't touched it. Even when I had the carburetor rebuilt they said nothing about it.
The trucks been backfiring bad lately I guess I know why now.

I put it back together with all 4 bolts and lock washers. I also found the passenger side exhaust flange loose again!

Back to first things first. I do not care what GM did on a 307??? It flat out woul d not stay that way on my rig.

I am sure you can find the correct gasket and studs and go from there.

I bought this screwy Dodge Dart a while back with the Slant Six. Went to do a oil change and tuneup leaned on the air cleaner and found the whole thing tilting.

Took the housing off to find the top of the carb barely had 2 screws holding the whole thing togetether.

Put the proper screws back in it after the oil change/tuneup and it ran no better.

**AussieinNC** · 10-28-2019, 07:21 PM

Quote:

Originally Posted by toolboxchev

Back to first things first. I do not care what GM did on a 307??? It flat out woul d not stay that way on my rig.

I am sure you can find the correct gasket and studs and go from there.

I bought this screwy Dodge Dart a while back with the Slant Six. Went to do a oil change and tuneup leaned on the air cleaner and found the whole thing tilting.

Took the housing off to find the top of the carb barely had 2 screws holding the whole thing togetether.

Put the proper screws back in it after the oil change/tuneup and it ran no better.

So what did you do with the Dart ? Slant 6 engines are almost unbreakable...usual issues include bad advance sets in the distributor, and manifold leaks air leaning out mixtures..the carbs were renowned for coming loos,,,red loctite stopped the issue....

**AussieinNC** · 10-28-2019, 07:22 PM

Quote:

Originally Posted by toolboxchev

Now I can tell, that IS a Vette Motor!

Sadly so many fall for the old "its a Corvette engine".....

toolboxchev · 10-28-2019, 07:28 PM

Unfortunately, I did sell it for next to nothing. Should have kept it as it was a 2 door.

Dodge was a sore subject in the household as Gramps took early retirement when Iacocca took over.

As with anything, someone is probably turning it into a 10K rig. Yea, that 6 always fired, never let me down no matter what was happening.

10-26-2019, 07:55 PM	#1
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,936	Does this look right? Took the carburetor off tonight and found it only had 2 bolts holding it down and both of them where loose. I thought dang 2 of them where either gone are broke off but not either one. The gasket only had 2 of the 4 bolt holes cut. It's been like this since I bought it cause I haven't touched it. Even when I had the carburetor rebuilt they said nothing about it. The trucks been backfiring bad lately I guess I know why now. I put it back together with all 4 bolts and lock washers. I also found the passenger side exhaust flange loose again! Attached Images __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

10-26-2019, 08:04 PM	#2
firedemon Registered User Join Date: Jun 2015 Location: @ Posts: 890	Re: Does this look right? I used to see holley 2 barrel carbs on mopar like that back in the day

10-26-2019, 08:05 PM	#3
AussieinNC Moderator Join Date: Jun 2017 Location: Cherryville, NC Posts: 2,193	Re: Does this look right? 2GC carbs sometimes only have two studs and nuts retaining them... probably a cost saving exercise.... Check out that wire laying along the intake under the accelerator rod...looks like its got bare sections that could ground out... Backfiring could be lots of things... Air leaks, bad accelerator pump, bad timing, bad timing chain... Start with basics,,,,check carb for lack of accelerator pump squirt, check timing, check for vacuum leaks... __________________ Family and country before all others... 2006 Chevy Silverado (Daily Driver) 2012 Chevy Equinox

10-26-2019, 10:40 PM	#6
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,936	Re: Does this look right? The intake is on a 350 but it's not the original motor for the truck. I'm going to a 4 barrel Elderbrock over the winter. But for now it will do. __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

10-27-2019, 07:44 AM	#7
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,859	Re: Does this look right? When does it backfire? __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

10-27-2019, 08:09 AM	#10
68 P.O.S. Registered User Join Date: Jan 2007 Location: Puyallup, WA Posts: 1,662	Re: Does this look right? I hope it's that simple as well. If so, double check the timing. It may have been adjusted to run with the carb the way it was __________________ 72 C10 lwb fleetside -stock 350/350 combo

10-27-2019, 12:53 PM	#14
Barnfind46 Registered User Join Date: Aug 2014 Location: Mena,Arkansas Posts: 485	Re: Does this look right? So it got upgraded to the super rare Corvette option! __________________ 68' with no bells or whistles unless I add'em.

10-27-2019, 02:26 PM	#16
firedemon Registered User Join Date: Jun 2015 Location: @ Posts: 890	Re: Does this look right? i have often wondered what all those old corvette are running for motors now that they have all been pulled and put in everything else

10-27-2019, 04:16 PM	#17
3767 Registered User Join Date: Aug 2019 Location: Vale,nc Posts: 169	Re: Does this look right? As mentioned by a previous post, timing or even a broke exhaust rocker arm/valve spring. Reason.....u said it backfired when u let off of it. If truck started ok and idled ok would have 2 b a small vacuum leak. A big 1 would show by a bad idle. Due to back fire being when u let up, loose manifold or something n the rocker arm exhaust valve. If u are gonna swap it for a 4 barrel, u may want to pull those valve covers and have a look at all of them . good luck andy.

10-27-2019, 05:23 PM	#18
rsavage Registered User Join Date: Aug 2009 Location: Alden NY Posts: 2,705	Re: Does this look right? I had one on the 305 I took out of my Blazer when I began stripping it out. Late 70's or 80's. Mine had an egr valve on the intake. Does yours Andy? __________________ 1961 C1 Corvette 1959 El Camino 350 TPI, 9" 4 w disc 69 Blazer K5 - sold July '20 2021 Durango RT 5.7

10-27-2019, 06:54 PM	#19
AussieinNC Moderator Join Date: Jun 2017 Location: Cherryville, NC Posts: 2,193	Re: Does this look right? Ahhh! The old Corvette 350 situation..... 1/ Corvettes with V8 engines never came with a 2 bbl carb 2/ The intake manifold looks like a 307 manifold....small port runners 3/ If you can, find the engine number, passenger side front of block on a pad level with where block meets head 4/ If you can, post a pic of the front face of the drivers side head showing the casting blocks 5/ Drivers side back of engine is a cast in number...post the number and we can identify the engine for you __________________ Family and country before all others... 2006 Chevy Silverado (Daily Driver) 2012 Chevy Equinox

10-28-2019, 06:28 PM	#21
toolboxchev Registered User Join Date: Jul 2015 Location: 2nd left past the stump on a dirt road. Posts: 2,629	Re: Does this look right? Now I can tell, that IS a Vette Motor!

10-28-2019, 07:28 PM	#25
toolboxchev Registered User Join Date: Jul 2015 Location: 2nd left past the stump on a dirt road. Posts: 2,629	Re: Does this look right? Unfortunately, I did sell it for next to nothing. Should have kept it as it was a 2 door. Dodge was a sore subject in the household as Gramps took early retirement when Iacocca took over. As with anything, someone is probably turning it into a 10K rig. Yea, that 6 always fired, never let me down no matter what was happening.



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