YES>> I REALLY HATE THESE TYPES OF THREADS... but now I am forced to make a choice for my daily driver. It's getting a 350 with a zz4 cam (or better) and ported vortec heads. My concern is fuel economy, being this the only car. I really hope that I get some honest results on this, or maybe the carb gurus can tell me that I'm over-reacting about gas mileage...

CARB; pros and cons
+ cheap and easy
+ tuneable in my driveway
+ more power in most cases
- meh, the gas mileage
- I have no clue about them or how to tune them
- have to get new fuel lines for under hood (hard lines are okay)
- requires a new distributor (vac advance)

TBI; pros and cons
+ better gas mileage
+ less adjustments to make
+ I retain torque converter lockup (without the $75 kit for carb)
+ novelty; it's a TBI
+ I know a lot about them
- a little more expensive (50mm throttle body + injectors + fuel pump = $350)
- tuning has to be done by someone else who doesn't have access to the car




will I need a new fuel pump if I swap to carb? can it feed my engine? I know I need a FPR, but will the fuel pump have to be replaced too?

 

why would you want to port vortecs they flow great out of the box. and even with the porting done they gain very little cfm. and i've seen some were they have made them flow wrose just a heads up

 

my buddy is selling them to me for cheap, and they're brand new never used. accepts .550 lift, has screw-in studs and guideplates, with mild porting (stock valves)







wtf at the server not updating the forum index

 

I'd keep the TBI and just get a mild EFI cam if you want economy. TBI can get the job done on a fairly hot setup but as you know it doesent give you full pontential and can cost. A carb isnt all that hard to dial in but most people are never happy and consantly tinkering under the hood for an extra few miles out of a gallon of gas, it gets old real quick. The TBI fuel pump doesent put out killer PSI so a cheap regulator would do the trick but one with a return line is a very nice feature.

 

I think I will go with carb... I'm leaning towards it. It seems SO much easier to play with, and has more power. Plus, if I don't leadfoot it everywhere what, I'll get maybe 3mpg less than TBI?

 

I prefer carbs. Its just easy to diagnose and repair if there is a problem and generally, thats not very often. All three of my cars are carb'ed. FI is nice for cold weather driving during engine warm-up but once you're used to a carb its not even an issue.

When I first got my '84 T/A back in 1998 I was getting around 18/23 MPG city/highway. That was a 14 year old car with no previous carb rebuild or adjustment. Now its in badly need of a rebuild but I'm still getting around 14/18 MPG.

My 71 T/A scored 17MPG on the highway with its big 7.6L 462 cu. in. engine, no overdrive, and 3.73 rear gears.

If you gotta go FI, tuned port is the only way to go.

 

as long as someone tells me I will get decent mileage... I will go carb I'm going to get an edelbrock 600cfm... should I get a manual or electric choke?

 

Here's something worth looking at, if you haven't already.
Is the edelbrock you're planning on getting one of the Qjet replacements, or a carter type?
https://www.thirdgen.org/techbb2/sho...hlight=biochem

 

carter type... the 1405 or 1406 is what I'm looking at.

 

Cool enough, just thought I'd ask... for the record.
They both have their strong and weak points.
I think Carters are the easiest to work on, which is a big plus if you're a rookie to carbs. That means you'd be more likely to get it dialed in right, which is key for fuel efficiency.

More:
There's a world of difference between the drivability of a carb and TBI.
The way a TBI drives, it feels like there's something wrong with it compared to a carb.
I suppose TBI tuners could get a TBI to behave like a carb, but I just like the way a carb feels.
That's a plus that you didn't mention.
Either manual or elect choke is good, get elect if you can afford it, you don't have to remember to open it up after the engine's warmed up.
I've driven too many miles with my manual choke on, just cause I spaced out.
The Mallory afpr is the one you want. (I forget the part#)

 

That's what I've been told. I hear you can squeeze an extra 10-15 hp out of a holley, but they're not as reliable and harder to tune.

I'm all for the reliability and efficiency part

 

Ive been running a holley 670 street avenger with my 350 for about six months now and I havent had any problems with it. I just bolted it on and adjusted the idle mixture screws and it rans perfect. There tuned a little rich out of the box but so far I havent fouled a single plug. I wouldnt go back to tbi if someone paid me.

 

On my new motor (less than 200 miles), I'm getting about 18-20 mpg with mostly highway driving. The basic parts are L98 shortblock, Trickflow 23* heads, LT4 Hot Cam kit, T-5, and 3.73 rear gears with a Holley VS 600cfm carb. It's still tuned a little to the rich side so it could do better. I, however have found myself wanting FI, but not tbi or tpi.