RnRK20

I'm new to the forum just picked up my dream of a 75 stingray last year. All original and stock. My boss (mechanic been working for 30 years and owns a 60 Bonneville) said he would rebuild my carb with bigger jets. I didn't know if anyone had any preferences of what to use. I'm all new to carbureted engines so go easy on me. Any advice would be greatly appreciated.

F22

I wouldn't do a single thing to the carb until I knew how it ran. Does it start easily? Typical technique I use when cold, is three pumps of the gas pedal to the floor, then hold the pedal down just a little, then turn the key and crank it. Should start right up.

I don't know what carb you have, or whether it has a choke or not, but if it has one, it should run at a higher rpm, than an idle, until it warms up. If it doesn't have a choke, or its disabled, then you'll have to manually keep the revs up, until it warms up. Shouldn't be more than three to four minutes, max, in either case. Once it warms up, the engine should idle at a reasonable RPM, typically, under 1k. Mind idles at 700, to 800 at all times.

While driving it, it shouldn't bog, die, rattle with detonation on acceleration or diesel when you shut it off. If your Corvette behaves like I've described, I wouldn't touch anything on the carb.

F22

Let me add this; when it's warm and you've been driving it around, let's say you're making a stop somewhere, like the gas station. When you restart the car, you shouldn't have to touch the gas pedal at all. It should start instantly with out any gas pedal input. Pumping a warmed up, carb'd car, will only invite trouble.

rcread

Typically, a stock engine wouldn't benefit from bigger jets, assuming you have the original carburetor with the original jets. I'm not saying it wouldn't benefit from a rebuild, but rejetting is only typically required if you are modifying other things.

bmotojoe

There were four different carburetors used on your 1975 depending on motor and transmission options.
1. L48 Engine, Automatic Transmission #7045222 Main Jets 72 Primary Rods 46 Secondary Rods CH
2. L48 Engine, Four Speed Transmission #7045223 Main Jets 72 Primary Rods 46 Secondary Rods CH
3. L82 Engine, Automatic Transmission #7045210 Main Jets 72 Primary Rods 44 Secondary Rods CH
4. L82 Engine, 4 Speed Transmission #7045211 Main Jets 72 Primary Rods 44 Secondary Rods CH
Whatever carburetor you have note the carburetor number call Cliff Riggles at Chifs High Performance. Tell him what your carb number is and he will put a kit together just for your application. I have used his services a number of times and will continue to be a return customer. Kits are around $50.00 plus shipping. He is a very busy guy so be patient.
http://www.cliffshighperformance.com/

RnRK20

Engine is a L82 with automatic trans.

As for how the vehicle runs. It gives me no problem starting up. On cold mornings after setting the choke it starts and runs fine. After its hot vehicle will restart with out setting choke or using any gas to start. Vehicle runs great. From what I know most things are stock. It does have a nice exhaust on it. But mainly stock. Eventually after cosmetic fixes are done I plan to go slightly more performance and add a couple things into it.

Tonight when I get home (I'm posting form work) I will check the part number on the carb to make sure its the stock carb.

F22

Sounds like you don't have to do a thing to it.

Hoosier C3 Guy

I just finished rebuilding the Q-Jet on my Cadillac 500 in my 3/4 Chevrolet truck. So, from my personal, recent experience, it can take an amount of time to get things dialed in. If you are not having any troubles, then, yes, by all means, leave it alone!

7T1vette

If someone thinks that sticking larger jets in the carb will make it 'go-faster', ..... it won't. It will only make it run too rich.

Leave the carb alone--until it really starts giving you trouble.

dochorsepower

I agree with antique wisdom, "if it ain't broke don't fix it".