1983 gmc carburetor - The 1947 - Present Chevrolet & GMC Truck Message Board Network

RapidRide2 · 10-14-2004, 07:32 PM

I will go to look at a 1983 gmc 1/2 ton 305 c.i. 4-barrel fleetside next weekend. If it is as clean as the well taken pics and runsout/ shifts out right i am probably going to buy it. I have decided to later on go with g.m's 260 h.p. crate motor maybe with a small hydraulic roller camshaft. I am leaning to stay with the q-jet carburetor because of the part throttle economy. My question is ,,,,,is this a quadrajet on the 83' gmc 305??? If so ,, is this year worth rebuilding/keeping???? Second,,, does this carb have a ton of vacuum lines off of it?? I kind of want to clean up some of the emissions/vacuum line garbage of the 83' era.

**swervin ervin** · 10-14-2004, 10:38 PM

First of all, good luck with the possible buy. Second, the 260 HP GM Goodwrench 350 is a flat tappet cam engine. No provision for a roller like the 87 up engines had. So a roller cam will cost you some big bucks if you decide to go that route.

Most likely, it's a Q-jet. I think some 305's came with 2 barrels but they were used on 3 on the tree low optioned trucks I think. The Q-jet on the 83 will be covered up with hoses and such. It will have a electric choke of course, but it will also have the dual capacity pump system. This consists of a valve in the carb with wires going to a switch mounted in the thermostat housing. This is not a bad thing, but it's not really needed. Just more crap in the way if you ask me. This was used to supply extral fuel to the accelerator during cold operation. I think it was intended on helping with cold running on these smogged to death small blocks.

It could be in good shape, but will most likely need rebuilding. If it has already been rebuilt, then this is usually a bad thing if the rebuilder didn't know what they were doing. It's hard to speculate on something without seeing it first. Don't sweat it though. There are a ton of used Q-jets in the junkyards that you can get for cheap and rebuild if the one on the truck isn't up to par. Of course there is the Edelbrock 1904 Q-jet that is the best route to go, but they are big bucks.

Good luck with everything and let us know how it turns out.

RapidRide2 · 10-15-2004, 06:47 PM

Will the edelbrock 1904 be the best carb for this application??? I guess i'll change intakes and get rid of the e.s.c. dist just for now. I guess i can get by with some type of edelbrock carb that is pretty much universal( i guess?) I wonder if all the edelbrock q-jets have the correct linkage for the t.v. cable and everything. Why are the edelbrock q-jets superior????,, Besides being brand new,,,, I don't mind spending a little extra if the quality is there. p.s. I know i would have to get a retro-fit roller for the 260 h.p crate engine. I just thought it would be something different sounding with a nice exhaust system along with more power to set it apart. Thanks Matt

**swervin ervin** · 10-15-2004, 09:35 PM

The 1904 is the carb you want from Edelbrock for a direct replacement of the stock Q-jet. I'm bias but IMO, there is no better carb for the street than a Q-jet. The Edelbrock's are the only way to get a new one. Sure, you can buy rebuilt ones, but they are rebuilt. Some will say they might be better than new 1904's. I say bull. I've got a 1904 on my truck and would buy one again in a NY minute. You could buy a 1406 or similar square bore Edelbrock and get by cheaper. They look real cool and are good carbs, but they are not Q-jets. You will not get as good of mileage or power from them. The small primaries of a Q-jet are great for normal driving and gas mileage and the big back barrels are fantastic for power. Rochester knew what they were doing when the designed them for sure. Never listen to anyone who calls them Q-junks and other names. They don't know how to tune them so they are junk to them.

Anyway, I highly recommend a 1904. If you don't mind paying the bucks for one, you sure won't regret ever doing it. I don't know about all the Edelbrock Q-jets, I'm assuming they would all work. But I do know the 1904 is a direct replacement for our stock ones, minus the dual capacity pump system of course.

Roller cams are a great addition to any engine no matter how big or powerful. You don't have to worry about the lifters and lobes wearing out like a flat tappet cam does. They are the only way to go for long duration and high lift. They can be ground with some real quick ramps that a regular cam/lifter combo couldn't be. Again, if you don't mind paying for a retro fit roller, you wouldn't regret ever doing it.

Mike

10-14-2004, 07:32 PM	#1
RapidRide2 Registered User Join Date: May 2004 Location: Saint Louis Posts: 76	1983 gmc carburetor I will go to look at a 1983 gmc 1/2 ton 305 c.i. 4-barrel fleetside next weekend. If it is as clean as the well taken pics and runsout/ shifts out right i am probably going to buy it. I have decided to later on go with g.m's 260 h.p. crate motor maybe with a small hydraulic roller camshaft. I am leaning to stay with the q-jet carburetor because of the part throttle economy. My question is ,,,,,is this a quadrajet on the 83' gmc 305??? If so ,, is this year worth rebuilding/keeping???? Second,,, does this carb have a ton of vacuum lines off of it?? I kind of want to clean up some of the emissions/vacuum line garbage of the 83' era.

10-14-2004, 10:38 PM	#2
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	First of all, good luck with the possible buy. Second, the 260 HP GM Goodwrench 350 is a flat tappet cam engine. No provision for a roller like the 87 up engines had. So a roller cam will cost you some big bucks if you decide to go that route. Most likely, it's a Q-jet. I think some 305's came with 2 barrels but they were used on 3 on the tree low optioned trucks I think. The Q-jet on the 83 will be covered up with hoses and such. It will have a electric choke of course, but it will also have the dual capacity pump system. This consists of a valve in the carb with wires going to a switch mounted in the thermostat housing. This is not a bad thing, but it's not really needed. Just more crap in the way if you ask me. This was used to supply extral fuel to the accelerator during cold operation. I think it was intended on helping with cold running on these smogged to death small blocks. It could be in good shape, but will most likely need rebuilding. If it has already been rebuilt, then this is usually a bad thing if the rebuilder didn't know what they were doing. It's hard to speculate on something without seeing it first. Don't sweat it though. There are a ton of used Q-jets in the junkyards that you can get for cheap and rebuild if the one on the truck isn't up to par. Of course there is the Edelbrock 1904 Q-jet that is the best route to go, but they are big bucks. Good luck with everything and let us know how it turns out. __________________ Mike 1985 Chevy C-10

10-15-2004, 06:47 PM	#3
RapidRide2 Registered User Join Date: May 2004 Location: Saint Louis Posts: 76	Will the edelbrock 1904 be the best carb for this application??? I guess i'll change intakes and get rid of the e.s.c. dist just for now. I guess i can get by with some type of edelbrock carb that is pretty much universal( i guess?) I wonder if all the edelbrock q-jets have the correct linkage for the t.v. cable and everything. Why are the edelbrock q-jets superior????,, Besides being brand new,,,, I don't mind spending a little extra if the quality is there. p.s. I know i would have to get a retro-fit roller for the 260 h.p crate engine. I just thought it would be something different sounding with a nice exhaust system along with more power to set it apart. Thanks Matt

10-15-2004, 09:35 PM	#4
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	The 1904 is the carb you want from Edelbrock for a direct replacement of the stock Q-jet. I'm bias but IMO, there is no better carb for the street than a Q-jet. The Edelbrock's are the only way to get a new one. Sure, you can buy rebuilt ones, but they are rebuilt. Some will say they might be better than new 1904's. I say bull. I've got a 1904 on my truck and would buy one again in a NY minute. You could buy a 1406 or similar square bore Edelbrock and get by cheaper. They look real cool and are good carbs, but they are not Q-jets. You will not get as good of mileage or power from them. The small primaries of a Q-jet are great for normal driving and gas mileage and the big back barrels are fantastic for power. Rochester knew what they were doing when the designed them for sure. Never listen to anyone who calls them Q-junks and other names. They don't know how to tune them so they are junk to them. Anyway, I highly recommend a 1904. If you don't mind paying the bucks for one, you sure won't regret ever doing it. I don't know about all the Edelbrock Q-jets, I'm assuming they would all work. But I do know the 1904 is a direct replacement for our stock ones, minus the dual capacity pump system of course. Roller cams are a great addition to any engine no matter how big or powerful. You don't have to worry about the lifters and lobes wearing out like a flat tappet cam does. They are the only way to go for long duration and high lift. They can be ground with some real quick ramps that a regular cam/lifter combo couldn't be. Again, if you don't mind paying for a retro fit roller, you wouldn't regret ever doing it. Mike



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