will a q-jet from a 305 work alright on a gmpp crate 350/290 hp

[slowpoke]

I have a gmpp crate 350/290 and bought the package deal which included an edelbrock 1405   600 cfm  and i was never satisfied with the carb performance so i tried a loaner 670 holley , that is what the manual calls for that came with the motor. it runs quite a bit better.
a guy has a q-jet that he wants to trade me but it came from a 305   do you guys think it would be worth rebuilding for the 350?
I have ask him to get me the numbers from it.
I am going to check to make sure the throttle shafts are tight in the plate.

[omaha]

   Yes, you can make that carb work quite well on that engine. It will need a few mods and changes to the setup but nothing too drastic. (I'd pass on it if it is a computer controlled carb though.)
    You may need to change the jet/rod combo and mybe "size down" the airbleed (if it has the large main airbleed). Also, I think (not 100% on this) that some of the 305 carbs had the secondary limited so that their throttle did not open all the way, limiting air flow. Even if this is so, this problem can be fixed also.
     The end result will be a carb that works much better on the street than aholley or edelbrock and will keep up with either of them on the dragstrip. The airflow potential is definitley there, you just gotta fine tune it to your engine. I'd sell the edelbrock, you could prolly get some good $ for it and buy several Q's at a swap meet for the same $. (the edelbrock is popular for the "bolt it on and it runs" mindset that guys have. However, that being said, it says nothin for the mixing ability of the carb itself. It really is not that efficient compared to the Qjet especially in the lower rpms and can cause premature engine wear due to the fuel washing tendencies (they were set up with a rich fuel curve so they could be used on a broad spectrum of setups). I'd get Cliff's book if yu dont have it already. (it answers the questions of "how")

[slowpoke]

the part numbers are 17059247    i take it as a 79 buick   but i decoded a standard shift" on a buick"

[Cliff Ruggles]

Nice carb, and a good choice for the crate engine.  It will need some help in a few areas, more plenty of carb for the application. 

It's a 79 Buick, most likely still an auto transmission carb, as the later Old's and Buick odd numbers didn't follow the common odd-manual, even-auto trans deal.

We have everything you would need to set it up exactly for the application.....thanks....Cliff

[slowpoke]

can you tell me what i need to set it up and I will order it. 

[Cliff Ruggles]

We take those orders over the phone, and select the parts based on the carb number and application, so have all the info ready when you call.

You will need one HP rebuild kit, jets, primary and secondary metering rods.

If the throttle shaft is loose, we sell a kit to install bushings, or will rebuild the throttle body for $45 if sent here.

Test the choke pull-off (primary) as well, it needs to hold vacuum and release in about 1.5-2 seconds.

If it's a hot air choke, it will easily convert to electric as well.....Cliff

[slowpoke]

it is hot air, i will get everything together and order soon. the primary shaft is pretty tight  I was a machinist by trade at one time and i barely can feel any slack in the primary shaft, how much is normal?
I would estimate a couple thousandths is what i have now it may be more when i get it apart and clean everything up.

[Cliff Ruggles]

It should have no more than about .008" side play.  Most will need bushings installed.  Make sure to open the throttle when doing the test.....Cliff

[slowpoke]

thanks I ordered a kit and the rods you suggested.  I was wondering which spring to use I should get the parts in a day or so. that was on the crate 350/290

[Cliff Ruggles]

Orange or light blue, they are designed for lower vacuum at idle.  I'd try the light blue first....Cliff

[slowpoke]

I have it rebuilt now and it runs alot better than the edelbrock/AFB and the holley 670  it is much more responsive and gets alot better MPG.  It is the close to fuel injection   I am having trouble with vapor lock on very hot days I put a fuel pressure gauge on the line and as i suspected the fuel pressure drops to zero when it gets very hot. I also installed an electric fuel pump and it still does it . I have rerouted the line and insulated it most of the way and it helped some I may try to put an insulator under the carb. I have an electric fan on the motor that comes on at 190 and I am thinking about putting a manual fan on it so it will push some cool air across the carb do you guys think this would help some??

[omaha]

yes, an insulating spacer is a good idea that i have not thought about til you mentioned it. Actually you can make one out of wood believe it or not. (Jim Hand's Pontiac book has a how to that is good).
 Believe it or not some manual fans work better for cooling than electric ones. Particularly if a shroud is used too. a friend of mine had that problem with his 67 mustang. he changed up to a flex fan and rerouted his fuel line. Got rid of the over heating and the vaporlock. It is seriously hot out hear in the Cornhusker state today. And on top  of that we got the Missouri river flooding.Our drag strip is under water!