carb opinion

[Pewter'01SS]

The main problem with Q-Jets is the "QuadraJet Bog". This is really what their infamous for. When you stomp on the gas, they will noticeably bog down the engine for a second or two before it kicks in. The lack of response is horrible. You can adjust them all you want but the problem won't go away. Now, not all Q-Jets are like this, but alot of them are. The one's that don't have this problem run great. I've seen a couple that had better response than any Holley I've run. Now if you don't want to keep readjusting your carb, Q-Jet's are the way to go. Set them once and if you roll the truck, you might have to adjust it again.

[GTStang]

I haven't messed wit carbs since back when I owned my 83GT.I think I'll stay out of brands unless you ask specifics of a certain carb, and give you a general outline. First thing is if your Blazer is an automatic I would stay away from any carb with mechanical secondaries. Next if you live in a cold weather area I would higly reccomend an electric choke for those cold winter first start ups. Also are you going to go off-roading in this Blazer and how serious... they make truck based carbs which fuel flow will not be effect when the vehicle is on steep inclines from off-roading. Finally what size to use... well there is the old stand-by formula:

CFM = Engine Size × RPM @ Peak Power × VE ÷ 3456

This forumla is not the end all to be all but it does help give you a general idea.

[89IROC&RS]

hmmm, come to mention it, i do remember that bog on my oldsmobile, but seeing as this isnt gonna be a race truck, that bog isnt a really big deal for me, if the carb is low maintanence it seems like a small trade off.

Also with the "seriousness" of the truck, im not gonna be rock crawling or anything like that, just four wheelin in the mud and snow on offroading trails and camping and stuff like that. So i dont think ill be rolling it over, at least i hope not.

[GTStang]

Originally Posted by 89IROC&RS

hmmm, come to mention it, i do remember that bog on my oldsmobile, but seeing as this isnt gonna be a race truck, that bog isnt a really big deal for me, if the carb is low maintanence it seems like a small trade off.

Also with the "seriousness" of the truck, im not gonna be rock crawling or anything like that, just four wheelin in the mud and snow on offroading trails and camping and stuff like that. So i dont think ill be rolling it over, at least i hope not.

Honestly you'd be surprised how little it takes to get your carb to lean out on you when off-roading. I far from rock crawl or ever came close to flippin my truck. But I have had the fuel cut-out on my while going up bumpy inclines with stock carbs. The combination of an incline and up and down jostling can wreak havoc easily. It's nothing major but it is annoying and when a carb made for off-roading usually is not a lot more it's worth it. If ya not using it for anythign but a winter commuter etc.., then you can save a few bucks.

[89IROC&RS]

ill look into that, thanx man.

[Hypsi87]

I know that the Q-jets on the Buick 455 stage one was the biggest q-jet avaible. Not sure of the size though. Also I am pretty sure that the Buick was the only one to get them on

[demon9766]

Originally Posted by 89IROC&RS

Im lookin to buy a early 70's Blazer (yeah not a camaro, but im talkin engines here, which are pretty much the same for the two vehicles) and seeing as its already all mechanical, im starting to look at the idea of running a carb instead of EFI to keep from having to do all the custom wiring and such. Problem is, i dont know jack about carbs except for the extream basics. So im wondering, what do yall suggest as the best balanced carb, in regards to performance, economy (gas mileage), and hassle free operation. Im pretty much leaning towards a Quadrajet, but i dont know how Holley and Edelbrock stack up. Or perhaps some other brand i dont know about. Ive got the camaro, so this isnt really a high hp strip engine, but its more for low RPM high torque for towing and off roading, but ill still be driving it on the street putting some highway miles on it. the base for the engine is a 383cid SBC with Vortec heads, dual plane intake manifold, and a cam with somewhere around .430/.450in lift. im lookin to get a carb with between 600-750cfm. but with the quadrajet i could run an 800cfm without worry cuz of how they operate. im just doin some brainstormin here, and open to ideas and input.

Well u helped me so i will try 2 help u if i can . I have tried a lot of carbs,and the best most hasle free carb on the market right now is a Demon, they are made by Barry Grant.For what u r tryin to do u might want to look at a Road Demon jr they get good gas mileage and have vacuum secondaries.ANd if u want a little more bang get the Road Demon, they have many differnt models. The only thing they are a little pricey the better the model.Hope this helps.

[GTStang]

Originally Posted by demon9766

Well u helped me so i will try 2 help u if i can . I have tried a lot of carbs,and the best most hasle free carb on the market right now is a Demon, they are made by Barry Grant.For what u r tryin to do u might want to look at a Road Demon jr they get good gas mileage and have vacuum secondaries.ANd if u want a little more bang get the Road Demon, they have many differnt models. The only thing they are a little pricey the better the model.Hope this helps.

I would stay away from Bary Grant carbs for a newbie to carbs. His company is one of my favorite carbs but they are well know and I will agree as the most difficult carbs to tune and get to run properly.

His carbs are Holley copies(he use to work for Holley and his first Demon's he got sued over cause they were so similiar) with a lot more tuning designed in which is why they so much more money. But it's a double-edge sword he gives you all this tuning ability so they expect you to use it.

So I think for what he wants it for it would just be a waste of money. And an exercise in aggrevaition.

[89IROC&RS]

yeah the demon carbs are the newest deal on the block, but like GTstang said, im a nooby, so im not ready for something that complex yet. appricate the info though.

[demon9766]

Originally Posted by 89IROC&RS

yeah the demon carbs are the newest deal on the block, but like GTstang said, im a nooby, so im not ready for something that complex yet. appricate the info though.

Well i guess u r right i forget that i have messed with carbs a long time,and if u don't anybody who knows a little about it it can be a pain.Well I guess a Q-Jet would be best. Just don't turn it upside down.

[pnyh8er]

Nobody that I have ever delt with as far as carbs will even touch a Q-Jet. For what I hear the general rule of thumd for them......expensive paperweight.

[Wattsyurz]

Most Quadrajets are junk for hobbyists. If you put it on and it doesn't run right, that's all you get. Drill the caps out, try to adjust... none of this ever helps much. For my '83 carb Camaro, I bought the Edelbrock. As people have said, it usually burns rich. I haven't tried to adjust the mixture yet, but the mixture screws and idle screws are accessible and bring back the feeling of being able to do something. If I get bored, I may get the aftermarket sprinkler to judge the difference.

[hellraiser319]

id go with a 750 and up aftermarket carb if you wanna go that route. thatd be the minimum for that size. tpi would be good since it has the low end torque, but tbi would be alot better. its a carb but 100 times better. you got the power of a carb and efficency of fuel injection. if you go tbi best bet would be a holley 4bbl tbi with 454 injectors. ud still need the computer and all that and probly a custom burnt chip but it would be worth it in the long run. just a thought tho....

[89IROC&RS]

well no argument that fuel injection would be the BEST way to go. although ill still give people who think TBI is the best available setup a weird sideways look lol. Im basicly looking to learn carbs this way cuz its an aspect of the automotive realm i dont know anything about. I had a Q-jet on my oldsmobile, and while it did have a little bog now that i think about it, i remember my uncle screwed with it to take power away so i didnt hurt myself, he was kinda a dick like that. Because i didnt know anything about carbs i couldnt fix it. My brothers bronco has an edelbrock carb on it, and it has run like shit since day one, and weve even taken it to the shop and had people work on it. but that was with a POS junkyard engine, now hes got a ford racing 302 to drop in, so well see how it runs on that. but i couldnt get that carb to run for shit, and neither could shops, so ive kinda got a bad taste in my mouth from them. as far as holley, i just dont know anything about em. I appriciate all the input guys, but i think ill just find me a used Q-jet, get the plans, and see what i can get out of her.

[black84z28]

for a carb you can't beat a 3310 holley...cheap...easy to tune and a vac sec for that automatic..


i had a 357 with vortec head,cc ee 274h and performer rpm vortec intake....it ran like crap until i put the 750 on it...