I have a 75 chevy with a 400ci?

Question

i want to take it to the mountains when i get back home to colorado but i dont know if it will make it cuz the carb. i dont know if i need a special one or what?

Answer 1

no u don't need a special carb. just keep in mind that when u get into higher elevations it may not perform as it did at lower levels. this is because the timing will need changed as well as the jetting and there's no 'puter in that year vehicle to do the job automatically.

u can expect lower performance and lower gas mileage while in the higher elevations.

Answer 2

There's not a Carter / Edelbrock Carburetor dead or alive that the has the overall capacity for performance or sharp everyday drive-ability as the Rochester Quadrajet. They are easy to tune and work on with a multitude of GM available floats, needles and seats, primary jets, metering rods and secondary metering rods.
Actually you'll be operating your truck at increased altitude which means you can get by with a slightly leaner air fuel mixture in the primary circuit. You can do either of two things. Install one size leaner primary jets or a slightly larger diameter primary metering rod up on the tip. The metering rod change will deliver slightly less fuel during steady state driving but at partial or full throttle crowds you get the OEM mixture. If you pull and inspect the primary and secondary metering rods you will see that depending on the degree of throttle opening governs how far out of the jets the rods raise. The rods have several steps and tapers to provide smooth air/ fuel mixture overlap between degrees of primary and secondary throttle opening.
If you ever desire to really get in to a Quadrajet, HP. Books has a great publication: Rochester Carburetors written by Doug Roe. Any Large book store can get it for you. It's worth it's weight in gold.

Answer 3

probably has a quadrajet on it.....the most cost effective and reasonable answer to that is to replace it with an edelbrock 4 barrel.....besides that truck was built in the era of leaded fuel and the 10% ethanol has probably done its dirty deed to the inside of the quadrajunk and to pay somebody that knows what they are doing to rebuild it will most likely exceed the cost of a new edelbrock

country boy made some intersting points but i never said high test gas i said leaded fuel and ethanol will destroy something that was designed for leaded fuel...that's beside the point...i won't argure driveability with a quadrajet you are correct...but you see somebody with a lack of experence with carburetors can seriously monkey up a quadrajet if they don't know what they are doing...besides the mixture screws on alot of them require a special "screwdriver" shall we say...and alot of the later ones (the electronically controlled i.e. 87 307 olds) had them blocked off...and if you are still going to insist that i have never worked on one you are grossley misinformed....thermoquads and quadrajets are of the same church but different pew ya know what i mean?...besides to replace one with a QUALITY reman carb is upwords of 400 dollars verses 275 for the edelbrock/carter veriety....i'm not wanting and argument nor am i trying to start one but money is getting harder to come by and i know what I would do....but if the thing works fine than RUN with it... if you want something more user friendly then that is where my suggestion comes in

Answer 4

If you own a carb car then you should know how to adjust your carb, its really not that hard.

Answer 5

no you don't need a special carburetor you can re-set that one for higher elevations,and it will run alright ,there adjustable for different elevations,good luck with it.