33s on a k5??

[k5blazerfan]

well i got a 84 k5blazer... i got a 305 with headers edelbrock performer intake and a carter competition series 750 afb carburetor... ok now i have a 4 speed muncie sm465 with a 208 t-case and a 3.73 reaerend... ok now that you know a little about my truck let me tell you a little bit more.. on tire size it came with 31x10.50 r15s  at thie time now it has p235/75/15 now i was wondering if i put the stock quadrajet back on it and 33s what i would get with mileage... or would i have to keep the carter carb to power those tires... im going for fuel economy and a somewhat mild off road look please help...

[fitz]

Keep in mind that when you install the 33"s your speedo will not be accurate unless you have it calibrated. Left uncalibrated it will be hard to determine true mpg's.
  I think it will be a trial and error routine to figure if the 33"s help or hurt your mileage. My first thought was that the bigger tire would hurt it but then again they will make your 3.73's act like 3.42's so it may balance out.
  If I had to guess of the top of my head I would put your truck at around 11mpg's with the 33"s on it. It's the nature of the beast, tough heavy trucks that are not very aerodynamic, although there are some diesel blazers with 3.08's claiming to get 20+ mpg's.

[k5blazerfan]

well you see i get about 14 all around with 235/75/15s but it came with 31x10.50s so i dunno your right thos bigger tire will throw my speedo off by like 5-8 mphs i dunno lol i was wonderin tho what would be a better carb my 750 carter competion series or the stocker i dunno thanks for your comment

[4x4orbust]

the stock quadrajets are a misunderstood bunch.    they are extremely reliable, and when adjusted properly will provide more mpg's, and hp than most other carbs.

[k5blazerfan]

thanks 4x4orbust thats what i was lookiing for lol yeah i dunno much bout em but i did know quadrajet= better mileage but i always thought they was underpowered lol but i tell ya it seems to work pretty good on my buddys blazer... yes were blazer enthusiasts lol he has an 83 with a 350 and an 87 with a tbi 350 and his son has a 76 with a 400 and lockers we love our blazers lol

[4x4orbust]

everyone loves blazers, including me!   i need a bed so i have a truck instead.    i have used other carbs, (holley, edelbrock) and can't say anything really bad about them, although the holley didn't like the offroad i was doing at the time.   but i have a always come back to the quadrajet.   i am not an expert on them, nor do i claim to be,  but i do know that they can perform better than the others,   just harder to set up and dial in. ( i actually had to pay someone that knew what they were doing to dial mine in.  he was an older mechanic, but a genius when it came to these carbs)

[k5blazerfan]

yeah them older mechanics are pretty smart bout carbs lol

[Irish_Alley]

with the quad they can flow up to 800 cfm, one of power blocks shows i think it was 4x4 just reran a rerun on the rebuild of a quad

[beastie_3]

with the quad they can flow up to 800 cfm, one of power blocks shows i think it was 4x4 just reran a rerun on the rebuild of a quad

I was just going to mention that. You might be able to find the show online on their site or you tube.

[k5blazerfan]

ok so im gonna stick with the carter but i need help on how to adjust the air/fuel mixture and i dont know were to look lol i tried searchin but couldnt find anything.. its a carter competition series afb and i dunno how to adjust it for a 305 any help will be appreciated thanks

[VileZambonie]

That carburetor would work on a 454 so I think you're a bit overcarb'd for a 305. Adjusting the idle mixture screws will only help give you a better idle quality it won't change your fuel metering off idle. If you want to do that you need to play with the jets and the metering rods which is simple on that carb.

[4x4orbust]

honestly you should buy a book that helps you with the adjustments on the carb.   there are a few different books, barnes and noble carries most of them.   i would suggest going there and leafing through a couple to see which one would suit your purpose.   

here is an example, and a good one to have.
http://www.amazon.com/Rebuild-Modify-Rochester-Quadrajet-Carburetors/dp/1932494189

[k5blazerfan]

thanks vile yeah like i said i dunno much about carbs i always thought air/fuel was always in use i know im a little over carbed for a 305 but thats how i got the truck i think its a 305 cause the alternator is on the wrong side for a 350 i think but i was told that it was a 350 transformed into a 383 wich makes sense cause it has alot i mean alot of power lol

[4x4Cowgirl]

I know when my boyfriend first got one of this blazers, it came sittin on 35s at stock height... It would rub a little but thats it.

[78 Chevyrado]

Fuel economy = 28" or smaller tires.   I did get a set of 33's to fit on my 87 2wd.  The only rubbed slightly on the front when at full turn while flexing.  it was a 2wd with the lightest duty suspension.