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Posted By: Riggs 305 questions from my G20 - May 17th 2021 12:33 am
Hello all!
In the 'introduce yourself' part of this site I have pictures of my engine bay of the G20 van. I am stumped as to what parts of the motor are. I am looking to simplify the engine bay and clean up all of the vacuum and EGR hoses. I am making this van a very basic drag race van. I know the chevy guys will jump down my throat, but I want to get rid of the quadrajet carb. I've rebuilt it but it still bogs during acceleration. I have included pictures of parts I have questions about. Some people have told me it has things to do with cruise control, and A/C. All of these things I want to remove/ don't need anyways. But if I can get some second and third opinions I would be very grateful.

There is a part behind and to the left of the carb.
There is another part that is on the other side of the engine bay that I was told had something to do with the cruise control.
The other part (black ball) in the front of the van, underneath the hood, I was told had something to do with heating and A/C

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Posted By: kursed Re: 305 questions from my G20 - May 18th 2021 1:04 pm
My suggestion, leave it be. I know that's not going to be a popular opinion, but if you don't even know what all of it is, why bother taking it off? Don't take my advice as demeaning either, read all the way through, I'm not trying to be nasty.

A big heavy brick of a van with a 305 which is not known to be a powerhouse of a motor, you're not going to gain incredible speed by removing any of it. I assume you'll be bracket racing anyway, which is won by consistency and accuracy, not speed.

Nothing wrong with a 305, I've got one in my 82 G10 project, but I installed it with intentions of cruising knowing that it's a mid 70's motor that is not known for incredible horsepower or torque.

I have a close friend that won street class championship at our local drag strip last year in an old worn out Dodge Omni. That thing is slow as molasses on a winter morning, but he has consistently great reaction times, and runs right on his dial-in almost every time.

Grab a repair manual and read through it to learn all those parts. They're all listed in there with a lot of illustrations as well. Practice running what you have for now, then if you get good and decide you want a ton of speed, you'll know which parts you're pulling and what they'll do.

Not trying to rain on your parade or be nasty either, so please don't take it that way. I've been working on cars, trucks, and bikes for 30+ years. I've also spent considerable time at the drag strips since the early 80's. I ran a 1967 C10 swb fleetside flat black and flamed with a 305, HEI, headers, and turbo mufflers. Ran a 600 Holley on it back in the day, and it would still barely outrun the 1991 Nissan Hardbody pickup I had at the same time. The Nissan mostly stock with 3:73 gear and a KA24 motor, 5 speed ran mid 10s in the 1/8th, and the 67 C10 with the 305 ran low 10s in the 1/8th. My 72 Chevelle with a 71 Z28 350 & th350 and 3:08 gear ran high 9s. The Nissan was the most consistent, so I won more trophies with that one believe it or not.
Posted By: 1983G20Van Re: 305 questions from my G20 - May 27th 2021 7:23 pm
Get Cliff Ruggles book on Q-Jets and learn to set them up properly. Properly setup they NEVER bog! Get a 218/218 @ 0.050, .450 lift, 106 LSA cam degree it in on a 98 ICL and put a performer rpm q-jet intake on it along with some headers. She will scoot after that. My 83 had a 700r4 and 3.08 gears in it and still ran strong. I ran low 10s in the summer and high 9s in cooler weather in the 1/8 and won alot of bracket races in mine. On 295/50s and 3.08s with a G80 it would dead hook race after race and the Q-Jet fed 305 was dead consistent once heat soaked. I had Thorley tri-ys on mine and had pipes fabricated by my local muffler shop to hook them to the factory catless 2.5" duals. Added a Dr Gas X pipe several feet in front of the factory mufflers. I played with the governor in the 700r4 and never could get it to shift exactly where I wanted it to on both the 1-2 and 2-3 shift but got it close. Auto shifted at 5,300 on 1-2 and 5,500 on 2-3. Running better than 80 when I hit the top of that ramp. 3.73 gears and a 2,500-3,000 rpm stall converter would have really woken it up on the launch.
Posted By: frscke1 Re: 305 questions from my G20 - May 27th 2021 7:35 pm
Originally Posted by Riggs
The other part (black ball) in the front of the van, underneath the hood, I was told had something to do with heating and A/C

That Black ball is part of the vac system DO NOT REMOVE IT ! !

There should be a vac line (5/16 rubber hose) attached to it.
Posted By: Riggs Re: 305 questions from my G20 - July 15th 2021 1:04 am
Kursed: No offense taken, Thanks for your input. As much as I'd like to leave it alone I know that won't happen, The excess in vacuum/EGR hoses just turns me off from wanting to work on the van. I want things to be simplistic. I don't see the reason for having 5 different vacuum hoses going into the carb when a Holley has two at most. Im not interested in legit racing, just having a street legal vehicle that is bare bones and can go run the drag strip on test and tune days.

1983G20Van: I know the Qjet carbs run well when they are in tip-top shape, but as stated above I want simplicity. I also did rebuild the carb with the help of Cliff's book, plus I spoke with him on the phone for a few minutes. It was my first rebuild of a carb ever, so maybe I need him to do the rebuild?

frscke1: If this part of the vacuum system is so important, why don't drag cars and other street cars not have this? If i traced all hoses back to where it connects with the 'vacuum ball' , why cant I remove and plug them all up?
Posted By: frscke1 Re: 305 questions from my G20 - July 15th 2021 2:08 am
vac has a lot to do with other things functioning its not just for the motor ... your old school mech working on a newer veh ... no offence ment just the big three were partying hard when they came up with some these ideas and a lot of it has to do with pollution ... thats why drag racers dont have them. I would it least cruise thru a repair manual to see what the vac hose do before pluggin them all ...
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